Shigaraki pots with fiery red surface and white feldspar spouting from them. Tanba pots and jars with fresh green glaze running down the ash-white surface, and Bizen pots with reddish-black surface and natural glaze in the color of decayed leaves. These are all well-known ceramics representative of medieval ceramics from western Japan. The shapes and colors of these vessels, which are in keeping with their respective regions, most clearly express the characteristics of medieval society, which was strongly influenced by regional characteristics.
In discussing these medieval ceramics from western Japan, I would like to point out in advance the position they occupy. As already mentioned in the Seto Mino volume, medieval pottery can be divided into three types: earthenware, Sue ware: and japanned ware. Medieval ceramics from western Japan, such as Iga, Shigaraki, Tamba, and Bizen, belong to the Jiyu ware series for the first three, and to the Sue ware series for Bizen.
The Sue ware type is, needless to say, derived from Sue ware: which was fired as hard pottery in various regions during the Heian period (794-1185). The second type of pottery is a grayish-black type of Sue ware produced by reduction firing, which is the same technique used to produce Sue ware. The pottery discussed in this volume belongs to the first of these two types.
The distinctive feature of the Sue ware type of medieval ceramics is that they were fired mainly in three types of vessel forms: jars, pots, and mortar. In general, medieval ceramics include tableware such as bowls, plates, bowls, and bottles, as well as storage vessels such as jars, pots for boiling, and a few Buddhist vessels. However, these types of vessels were not fired uniformly in all kiln sites. In the Bizen kiln, bowls, plates, and vases were fired in the very early period, but from the mid Kamakura period onward, pottery was mostly limited to jars, pots, and mortar, with only a few Buddhist vessels also being fired. The types of vessels produced in Iga, Shigaraki, Tamba, and other areas, where the actual period of occurrence is not yet known, are unknown. As far as is currently known, pottery is limited to three types: jars, pots, and mortar. In the late Muromachi period, new products such as kataguchi small jars ōke and tokuri vases appeared, while tea ceramics began to be fired with the popularity of wabicha (tea ceremony). Excluding Mino, Seto, and other glazed ceramics, tea ceremony ceramics were fired among the unglazed wakizome ceramics of the medieval period, a characteristic of the kilns in western Japan. Shigaraki and Bizen, in particular, have been mentioned early in tea ceremony records, which may indicate the advanced nature of these regions, which had a close relationship with the Kinai region from ancient times.
However, the three main types of medieval pottery are jars and ground bowls.
Why do these three types of vessels stand out in the medieval period, while other types of vessels were produced before and after the three types of vessels?
Looking at the function of each type of vessel, it goes without saying that jars have been developed as storage containers since Sue ware.
However, it should be noted that in the medieval period, jars were closely associated with agriculture, as shown by the term “seed jar. In addition to the storage of seed rice for sowing, it was also used for soaking seeds to accelerate germination during sowing. With the spread of double cropping since the end of the Heian period (794-1185), soaking rice before sowing is thought to have had a significant effect on the growth of the rice plant. Jars are also indispensable storage vessels in daily life, either as water jars or as containers for brewing sake. On the other hand, the development of fertilizer cultivation techniques in rural villages during the medieval period is thought to have increased the function of the jar as a fertilizer jar. The main type of fertilizer that gradually came to be used after the Heian period (794-1185) was grass and wood ash, but it is thought that the use of manure began in the Kamakura period (1185-1333). In the “Sasekishu” written around the end of the Kamakura period (1185-1333), there is a story in which dung is carried by horses to fill rice paddies, and in the “Nui Fudo Engi” written in the Muromachi period (1333-1573), a jar is shown buried in a corner of a garden, and Keigo Hozuki has already estimated that the use of human waste and urine had begun (“Industry and Technology in the Middle Ages and Technology in the Middle Ages” in “Iwanami Koza Nihon Rekishi 8”). This is a point that should be considered in conjunction with the fact that some jars became particularly large in size from the middle of the Kamakura period onward. In addition, the mortar and pestle were indispensable utensils for cooking in daily life. All three types of ceramics are daily utensils, and their close connection to agriculture is what makes medieval ceramics unique. It is well known that the development of agricultural technology in the Middle Ages revolved around the development of irrigation facilities and the intensification of arable land. The water wheel, introduced from China in the early Heian period, became widespread in the Middle Ages. The intensification of agriculture also led to the improvement of rice varieties, and the development of double cropping led to advances in the cultivation of minor grains. Furthermore, the development of double cropping led to the promotion of cultivation and the development of fertilization techniques to maintain soil fertility, as mentioned above. In addition, the remarkable spread of iron farm tools and the penetration of ox- and horse-drawn plowing played a major role in increasing agricultural productivity. The prosperity of farming villages that accompanied the development of such agricultural technology began to be noticeable from the late Heian period (794-1185) and developed on a nationwide scale in the 12th century. With this as a background, the relationship between supply and demand for pots, jars, and mortars is easy to understand. Jars and pots were not only produced for agricultural use. One of the major areas of use was as religious tools. Surveys in various regions have revealed that since the late Heian period (794-1185), jars and pots were widely used as containers for sutra casks in the construction of sutra mounds, and as bone implements for cremation. In particular, the amount of jars and pots used as cremation containers is enormous in Shigaraki, Tanba, and Bizen. It is not uncommon to find dozens of these vessels even in a single small cemetery. If undiscovered and unexplored items are taken into account, the quantity is enormous. Another example of a relatively large number of finds is the use of sen-jars. Among the medieval ceramics in western Japan, the use of coin jars is particularly well known in Tamba. With the increase in agricultural productivity from the end of the Heian period onward, the tendency to commercialize surplus products became more pronounced in the Kamakura period (1185-1333). In particular, with the importation of large quantities of Song coins through trade between Japan and the Sung dynasty (960-1279), the use of jars for storing coins was another indispensable aspect of this trend, which spread from urban to rural areas as the years went by.
Let us now take a comprehensive look at the characteristics of medieval pottery production techniques in western Japan. First, the clay used in Shigaraki, Tanba, and Bizen ceramics is characterized by a higher degree of refractoriness than that of Sue ware. The clay used for Sue ware was Pleistocene clay exposed on the low hills around the plain, but in the Middle Ages, the location of kilns was changed, and clay from the Neogene layer on higher hills was sought. This was probably due to the need for strength suitable for making large objects in accordance with the functions mentioned above. In both cases, the clay was mountain clay alone until the middle of the Muromachi period, but in the late Muromachi period, it began to be mixed with rice field clay, without exception. In terms of molding, Sue ware jars were wheel-thrown, whereas medieval jars were made by rolling up clay cords to form the basic shape and then adjusting the vessel surface with wood. Large jars and pots were formed by spreading sand on a wooden base, first making a circular base plate, then rolling up clay strings along the perimeter, allowing them to dry once they reached a certain height, and then grafting more strings on top. The surface of the vessel was then shaved with a trowel and adjusted vertically and horizontally with a mokurei. In terms of firing techniques, Sue ware kilns are usually constructed by drilling long, narrow trenches into the hillside and building side walls and ceilings with clay containing tin. At first glance, Shigaraki kilns look similar to those in the Tokai region, but they have dug large trenches and built a central wall and ceiling. Also, in terms of firing method, while the firing method of the Jiyu ware type was similar to reducing to oxidizing firing, the firing method of the kilns in western Japan was characterized by reducing firing in the early stages and reducing to oxidizing firing from the middle to late Kamakura period.
Shigaraki
A number of Shigaraki pots with white feldspar blown out over the entire surface of the red fire-colored vessel skin, as well as large vases and washi with hinogaki patterns painted on the shoulders in thick carving, are among the most attractive of medieval pottery. As is well known, Shigaraki pottery was produced in Shigaraki-cho, Koka City, Shiga Prefecture, a mountainous basin jutting out into the southernmost part of Shiga Prefecture. It is a narrow and long region from north to south, bordered by Iga City in Mie Prefecture to the southeast and Wazuka Town, Souraku County, Kyoto Prefecture to the southwest.
Despite Shigaraki’s prominence, it is still unclear when and how it was established. Shigaraki as a medieval ceramic artifact has yet to be traced back to the mid Kamakura period or earlier. With the exception of sutra tubes from the Heian period (794-1185), most of the intermediate objects connecting Shigaraki with Sue ware and ash-glazed ceramics are unknown. However, considering that all other medieval ceramic sites converted from the ancient style at the end of the Heian period, it is unlikely that Shigaraki alone was a latecomer. The ancient kiln industry in Omi Province mainly produced Sue ware at the Kagamitani kiln sites since the end of the 5th century, but these kilns gradually moved southward, firing green-glazed ware at the Sakutani kiln in Hino Town, Gamo-gun and the Yamagami kiln in Kasuga Town, Koka City after the mid-Heian period, and ash ware at the latter kiln as well, suggesting that the influence of the Owari ceramics kilns was felt. It is now known that the influence of the Owari ceramics kilns was also present in the latter kiln. Crossing the Yasu River from Mizuguchi Town, one mountain away is the Shigaraki basin. The form of medieval Shigaraki pottery is very similar to that of Tokoname, and it is clear that it belongs to the category of “瓷器” medieval pottery, but it is highly likely that the origin of this pottery can be traced back to the middle to late Heian period in the northern part of Japan.
Distribution of Shigaraki Kilns
The distribution of Shigaraki kiln sites has been confirmed at 185 locations between Miyamachi in the northern part of Shigaraki Town in the north and the Nagano and Kamiyama areas in the south. Of these, 46 belong to the medieval period, including a group of four kilns such as the Nakaide Kiln in Miya-machi, and the number of individual kiln sites is thought to exceed 100. These 46 kiln sites are not uniformly distributed in the long north-south Shigaraki basin, but rather are grouped into five major groups. The first group is located in the Miyamachi district in the northernmost part of the city, and consists of 12 sites north of a line connecting the Oto and Hayato Rivers, which run east to west. The second group is centered around Kise and Maki, where the Oto and Hayato Rivers converge, and six ancient kiln sites are known to be located west of the river and one east of the river in Nakamaki. The third group is the Teshi area, with a total of 12 sites, nine in Kawanishi and three in Udade in Kawahigashi. The fourth group consists of ten sites, eight in the mountains west of Nagano, the central town of Shigaraki Town, and two to the east.
The fifth group is located in the Kamiyama district bordering Mie Prefecture on the southeastern edge of Shigaraki Town, with one site in Kitashinden and three sites in Goinoki, for a total of four sites. In addition, there is one known site of an old kiln in Osuenohira on the Mie Prefecture side, beyond the Goinoki Pass in the eastern part of the town.
Shigaraki Products
The main products of the medieval Shigaraki kilns, like those of other medieval kilns except Seto Mino, are three types of jars, pots, and mortar. Tableware and cooking utensils such as bowls and bowls are extremely rare. In the late Muromachi period (1333-1573), however, in addition to the above three types of vessels, new types of vessels such as oke, tokuri vases, etc. were added, although only a few new types were produced. A few special types of Buddhist vessels such as sutra case, reliquary, and jar were also produced.
Of the above three types of vessels, the most numerous are large, medium, and small jars. Large jars are 35-50 cm tall, but large jars larger than 50 cm are often found. Medium jars are 20 to 35 cm in height. Small jars are less than 20 cm, but often around 15 cm. In terms of form, these types of jars can be divided into two types: round-bodied jars with a rounded and bulging body and long-bodied jars with a slender body and sloping shoulders. These two types of vase forms are common to medieval ceramics from western Japan. Shigaraki jars have more varied mouth forms than other medieval ceramics. The mouth rim is rounded at the edge, the mouth rim is twisted outward to form a so-called “N” shape in cross section, the mouth rim has a protruding band or concave surface just below the edge, the mouth rim has a concave line on the inside surface, and the mouth rim is bent outward in a rounded ball-rimmed style. The mouth rim edge is rounded outward in a ball-rimmed style. There are two types of jars, large and small. Large jars are 50-60 cm tall, with a large diameter in proportion to the body, and many have an N-shaped mouth rim similar to that of Tokoname jars. In particular, many of the early jars before the middle of the Kamakura period are similar to Tokoname, but those with wider rims tend to warp inward, with the lower edge of the jar adhering to the neck. Small jars are 25-30 cm in height and have a variety of mouth rims, such as a twisted back, a double-lobed mouth, and a ball-shaped rim. In the late Muromachi period, small round-bodied, flat-bottomed jars called iido-jars were also produced. Of the pots, the majority are suribachi, or mortar bowls. Suribachi are flat-bottomed, single-mouthed, with part of the rim of the mouth of a large flat bowl, a common feature of medieval pottery, and the interior of Kamakura-period suribachi does not have a grated surface. From the Nanbokucho period, sparse grated decoration with comb patterns began to appear.
In addition, kataguchi-kotsu (small jars with a single mouth) became increasingly common from the Nanbokucho period to the Muromachi period (1333-1573). These are common in other medieval kilns as well, with some having a thick, bulging body and others having a slender body, but they do not have the large tobiguchi (top) as those of Bizen, and the kataguchi portion is small. Another type that emerged after the mid-Muromachi period is the cylindrical oke (tub). The early version of what is called “onioke mizusashi” is also a conversion of the oke. From the late Muromachi to the Momoyama period, various types of tea ceramics as well as large bowls and flower vases began to be produced. Shouldered jars, or osenbe jars, are another type of jar characteristic of Shigaraki pottery from this period.
Shigaraki Production Techniques
The mountains surrounding the Shigaraki basin are granite areas. The clay used in Shigaraki is commonly known as frog clay or wood-block clay, which is highly refractory and rich in quartz feldspar and belongs to the Neogene or Pliocene Pleistocene strata derived from granite. Of the long, narrow basin stretching from north to south, those from the Kise area in the north have high iron content and relatively few quartz feldspar particles, and most of them are blackish brown or blackish purple in appearance after firing. Those in the central area, from Teshi to Nagano, have a red fire color characteristic of Shigaraki, and many of them have a lot of blown out quartz feldspar. The clay from the Kitashinden area in the southeast, from Goinoki to the Makiyama area in Iga territory, contains an extremely high amount of feldspar, and many pieces fired at a high firing temperature have a bluish-white glaze with a mixture of naturally falling ash and feldspar.
In the case of jars and pots, a circular base plate is first made, and then a thick clay cord is rolled up to a certain height, and after drying to a certain extent, the clay is added to the base plate. Small vases are water-ground on the potter’s wheel by hand. The most characteristic design on the vessel surface is a thickly painted hinogaki or nawame pattern on the shoulder. This pattern is found only on large, medium, and small vases.
A few small and medium-sized vases are known to be decorated with degenerate tree patterns. Rarely, some of them are painted with a bird design on the shoulder.
The firing of vessels was done in cellar kilns built into the slopes of hillsides. Shigaraki is said to have two types of kilns: a single-chamber kiln and a twin-chamber kiln with a long, vertical barrier in the center of the firing chamber, dividing the chamber in two. The structure of the Nakaide No. 1 kiln excavated by the author at the end of the Muromachi period is as follows: a 4m wide pit was dug into the slope of a hill, and a barrier with a core made of stones the size of a human head was placed in the center of the firing chamber, on which a ceiling was built. It is a large kiln. The kiln is known to have had a kiln structure that could withstand high firing temperatures, as both side walls of the combustion chamber are covered with pasted stones.
Changes in Shigaraki Kilns
The transition of Shigaraki kilns in the Middle Ages can be divided into five phases: I. Middle to Late Kamakura Period, II. End of Kamakura Period to Nanbokucho Period, III. Early Muromachi Period, IV. In recent years, a number of medieval cemetery excavations in Omi and Iga have revealed many examples of jarotsuki vessels from the late Heian to early Kamakura periods, but as seen in the presence of sutra case outer vessels excavated from Yokogawa, Hieizan, it is difficult to believe that this period was a blank period, and thus the research is insufficient. The earliest known example excavated from a medieval cemetery is a medium-sized jar excavated from the Butsudoji cemetery in Iga City, Mie Prefecture, which dates back to the middle of the Kamakura period (1185-1333). The earliest known excavation of an old kiln site is the Nihonmaru kiln in the western part of the Nagano area (Group 4), which dates back to the middle of the Kamakura period. The second is the Hanshi Kiln at the southeast end of the Miyamachi area (Group 1), where jars from the middle Kamakura period have also been found. Both are very similar to those found in Tokoname in terms of form and mouthwork. In particular, the striking patterns on the shoulders of the Hanshigama jars are similar to those found in Tokoname. The fact that the oldest kiln sites have been discovered at the northern and southern ends of the Shigaraki kiln is extremely important when considering the origin of the Shigaraki kiln. Shigaraki became most prominent in the artifacts from the end of the Kamakura period (II) to the Nanbokucho period (III). One of the most clearly dated examples from this period is a jar excavated from a medieval cemetery in Shiga Prefecture and inscribed in ink in the 2nd year of the Oan period.
This wide-mouthed jar with a wide, inwardly warped rim band and an arithmetic ball-shaped body can be considered typical of the Nanboku-cho period. From this period, large jars of two types, round-bodied and long-bodied, with or without hinokagaki inscriptions, were produced. In large jars as well, the N-shaped rim band is closely attached to the neck and warps inward. Grinding bowls are rarely grated, but there are rare examples with three coarse grits. The Kitashinden kiln in the Kamiyama area is a representative example of an old kiln site. The Kitashinden kilns are a group of old kiln sites that continued to burn until around the late Muromachi period (1333-1568). Many of the large jars clearly show the steps of hagi-zukuri during the molding process. The most representative examples from the middle Muromachi period of the IV period are a suribachi and a kurakotsu jar with an ink inscription dated 1458 (Choroku 2), which have been well known for a long time. The grating on the interior of the mortar is still coarse. The jar has a wide mouth in relation to the body, and the rim of the mouth has a band that adheres closely to the neck. Jars made in the jade-rim style have already appeared in this period, although they are somewhat outwardly warped. The Minamimatsuo kiln in the Nagano area, which has already been excavated, is well known as an old kiln site, and is a twin-body cellar kiln. The production of Shigaraki kilns from this period is widely distributed across various groups, and this is the period when Shigaraki kiln production was at its greatest expansion. A small jar with a short, tightened neck and a ground bowl with or without a grater is known as a standard piece from the late Muromachi period of the V period (1558). It is a long-bodied jar with rounded shoulders, and the mouth rim is made in a jade green style. It is inscribed with the inscription, “Eiroku, 1st year of Eiroku, September, Yoshinichi, Shigaraki, by Someshi Mansuke. In addition to jars of the style immediately following this one, the excavated Nakaide kiln also produced a rice jar with a horizontal line on the body, an oke, a flower vase, and other wares.
There are two types of ground bowls, one large and one small, both of which are densely grated and crossed at the inner bottom. The former kiln produced jars with upright mouths and necks, shallow bowls with bulging bodies, and large jars with Bizen-style mouth rims. The latter kiln also produced bowls and large shallow bowls, all of which suggest that there were exchanges with Bizen and Tamba.
Bizen
In 1977, a large quantity of Kobizen was discovered on the northern slope of Mizunoko Iwa, 6 km east of Shodoshima Island, Kagawa Prefecture, and was salvaged by Japan’s first underwater archaeological survey, attracting a great deal of attention.
The salvaged Kobizen ware, which consisted of 210 solid pieces of ten types of vessels, including jars, pots, and mortars, all of which were produced at the same time, were presumed to have been misrouted while sailing to the place of consumption, collided with Mizunoko Iwa, which was hidden between the waves, and sank. This is the largest find of its kind since it was salvaged from the bottom of Naoshima, Kagawa Prefecture, in 1940. Traditionally, Kobizen pieces salvaged from the seabed have been referred to as “Umiagegari,” and are highly valued as valuable documents that show the distribution of Bizen. Kobizen is at the other extreme because it is the only pottery that has continued to be made in the Sue ware tradition while remaining unglazed and unglazed. The representative examples of medieval Bizen ware were jars, pots, and suribachi (mortar and pestle), which had a red fire-colored surface and were covered with a dark green natural glaze. In the Nanbokucho period, Sadayo Imagawa wrote in his book “Michiyoburi” (The Road to the North and South), “Kagatotsu-fu-sato is a place where every house makes tamadare no kogame (jar with a ball-shaped rim) and toburi (earthenware with a rounded top).
Needless to say, the Bizen kilns of the medieval period were derived from the Sue ware kilns of the Heian period, but there are almost no Sue ware kilns in the area where the Bizen kilns were distributed.
As is well known, the mother of the Bizen kilns was the Oku Kiln Site Group, which developed in the inland hills from Nagafune-cho, Oku-cho, Setouchi City, downstream of the Furui River, to a part of Bizen City. The Oku Kiln Site Group was the largest Sue ware kiln site group in the Chugoku Region, which flourished from the Kofun Period to the beginning of the Heian Period. Recently, Sue ware kilns from the late Heian period have been discovered in the area from Nishioka to Yamada in Osafune-cho and on the hillside east of Yurusugi to the south of Nishioka, suggesting that these potters entered Ibe one after another via routes such as over Fukuda, Isaka Pass, or Hase.
Distribution of Bizen Kilns
Bizen ware was produced in the Kagatsu (香々登), or Kadonosho, area centered on Ibe, Bizen City, Okayama Prefecture, and the mountains around the foot of Mt. The Bizen kiln sites are scattered over an area of 3 km from east to west and 5 km from north to south, extending from the surrounding mountains surrounding the city of Ibe to the far reaches of the valley from north to south. At present, more than 80 old kiln sites have been discovered, and a detailed survey of each group would more than double the total number of sites.
The Bizen kilns are distributed in three major areas. The first is along the valley extending northward from the northwestern part of the city of Ibe to the eastern foot of Kumayama, and the second is on the eastern side of Furoyama, which extends northward toward the city center.
Another group is formed by the area from the southern hills of the city to the Uraibe area. Kilns have been continuously built in each of these areas since the end of the Heian period (794-1185), and these kilns were succeeded by the Nishi-Daiyama, Kita-Daiyama, and Minami-Daiyama kilns of the Momoyama period (1573-1600).
Looking at the transition of the northwestern area centering on the Nishi Dai-kiln, we can see that the Ikenada kiln on the northern slope of Oga-ike, located at the western entrance of Bizen City, was the starting point at the end of the Heian period, and moved to Daimyojin at the western foot of Mt. Later, the kiln expanded further northward to the Guibigaya Kiln at the eastern foot of Kumayama at the end of the Kamakura period.
In the Muromachi period (1333-1573), the kilns moved southward to the Bogaike Kita Kiln at the eastern foot of Iouzan in the mid to late Muromachi period, and then to the Nishi Dai Kiln in the Momoyama period (1573-1573). The Kita Dai-kiln group is thought to have diverged from the Daimyojin kiln, but its transition is not yet clear.
On the other hand, the Minamidaigama group is thought to have started from the Ogaike Minamigama on the northern slope of the hill facing the JR Ako Line south of Ogaike and moved eastward, and then settled in the Minamidaigama after moving from place to place in this valley at the foot of Mt. The relationship with the Minamidaigama kiln is not clear.
Bizen Kiln Products
Like other medieval kilns except Seto, the Bizen kilns of the Middle Ages mainly fired jars, pots, and mortar. However, in the early period, they also fired bowls, plates, and vases, showing a clear continuity with Sue ware. In the late Muromachi period (1333-1573), they began to produce vases and water jars before other kilns.
The most basic type of jar was inherited from Sue ware: with the outside of the mouth rim being about 20 cm in height.
As they became larger in size, the mouth rim was later turned outward and turned into a jade rim by folding the rim outward. These are tea jars. At some time around the same time, small jars with a partially folded, one-lobed mouth began to be produced. There are various large, medium, and small types of this vessel type, many of which have 箟描 patterns.
There are two types of jars (large and small), both of which were converted from Sue ware jars. Large jars are flat-bottomed jars with a height of 60 cm or more, with a large ball-rim at the tip of the upright orifice and a rounded, bulging body, the outer surface of which is adjusted with wood. Small jars, usually contained in jars, were called “tamadare no kogame” (meaning “small jar” in Japanese), and were wide-mouthed with a short outer neck with a ball-rimmed tip and a sunken line or comb pattern on the shoulder. Suribachi are similar to other medieval kilns, with the mouth rim of a large flat bowl partially folded over to form a single-mouth shape. The mouth rim band became enlarged around the middle of the Muromachi period (1333-1573), and by the Momoyama period (1573-1573), a wide range of bowls with several concave lines were produced. Bowls made only in the early period are flat-bottomed bowls with a diameter of around 15 cm and a height of around 5 cm, following the Sue ware bowls of the late Heian period. Plates are also shallow flat-bottomed with a diameter of 8 to 10 cm. In addition, large vessels and water bottles over 40 cm in diameter were also produced in the early period.
In the late Muromachi period (1333-1573), vases with large trumpet-shaped mouths and necks reminiscent of bronze vessels were produced as Buddhist vessels, and it is thought that the production of vases copied from Chinese porcelain began early in the Seto and Mino large kilns as prototypes for tokuri. In addition, tea bowls, tea containers, flower vases, water jars, and other tea utensils were produced during the Momoyama period (1573-1600), in line with the popularity of wabicha (tea ceremony in the wabi-cha style).
Bizen Pottery Production Techniques
The production techniques of Bizen ware are basically the same as those used in other medieval ceramics. While Sue ware of the previous period was made of Pleistocene clay from the hills around the inland plains, Bizen ware is made of highly refractory clay derived from granite in the Ibe area. In the late Muromachi period, the clay was mixed with rice field clay. In the molding of jars, a base plate was first made, then clay strings were rolled up to form the basic shape by several steps of body joints, and the surface of the vessel was prepared by shaving and adjusting the wood. The mouths of Bizen ware jars are less varied than those of other medieval ceramics, and are almost exclusively of one type, with the initial fold at the edge of the mouth rim gradually changing to a ball rim. The jars are basically the same as the pots, but the large jars are made of thick clay cords rolled up and piled on top of each other, and the surfaces of the jars are characterized by the use of sago-fir and wood adjustments. Suribachi (ground bowls) are also made of clay, but from around the middle of the Muromachi period (1333-1573), as they became larger in size, their mouth rims tended to become enlarged. Smaller jars were wheel-thrown and water-wheeled in the late Muromachi period. From the Momoyama period (1573-1600), the surfaces of jars began to be coated with clay, which eventually gave way to the Ibe technique.
The kilns used for firing were long, narrow, simple cellar kilns similar to Sue ware kilns, usually around 10 m long with a floor inclination of 15 to 20 degrees, but some kilns reached 30 degrees. In the mid-Muromachi period and later, so-called large kilns, such as the Furo Sando Kiln, were built 40 m long, 2.5 to 3 m wide, and with a floor inclination of 15 degrees, and eventually, in the Momoyama period, large kilns as long as 52 m appeared, such as the Nandai Kiln. Until the middle of the Kamakura period, Bizen ware of the Middle Ages was fired by reduction firing, which followed the technique of Sue ware: and the products had a grayish-ink color, but in the Kamakura period, the firing process changed to oxidation firing, and the unique red fire color of Kobizen became apparent. Bizen kilns have been efficiently packed since the Kamakura period (1185-1333), and there are many pieces that show traces of over-firing and the so-called “peony rice cake” mottled marks caused by the gapless packing method.
While other medieval kilns were strongly influenced by the Tokai kilns in terms of vessel shape and firing techniques, Bizen ware was a highly distinctive type of medieval pottery in that it followed the Sue ware technique and developed it in its own way, and it has remained an unglazed, fired ware to this day. Bizen ware was a very unique type of pottery among medieval ceramics.
Changes in Bizen Pottery
Bizen ware is known to have undergone six stages of transition during the medieval period. The six phases are: I. Late Heian to early Kamakura Period, II. early to mid Kamakura Period, III. late Kamakura Period to Nanbokucho Period, IV. early to mid Muromachi Period, V. late Muromachi Period to late Muromachi Period, and VI. late Muromachi Period to Momoyama Period. Early Bizen ware from Period I to II was still reduction firing, with a grayish-black color tone, and only a few bowls, plates, vessels, and water jars were fired, indicating that the Sue ware tradition of the previous period is still preserved. In terms of form, many of the wares from Phase I are difficult to distinguish from Sue ware. The red fire color characteristic of Bizen ware became apparent in the III period, and the double chink marks on the shoulders of jars gradually increased in number, and eventually changed to comb marks to decorate the surface of the vessels. Also in this period, kilns spread from the western part of the Bizen City basin to the deep valleys in the north and southeast, rapidly expanding their production. The Bizen kilns, which had until then competed with the Uozumi kilns in Settsu, the Kameyama kilns in Bichu, and the Katsumada kilns in Mimasaka, and remained a regional ceramic center, began to drive out these kilns at this time, and further developed into a major ceramic center that replaced Tokoname ware, which covered a large area of western Japan. In the Muromachi period (1333-1573), the Bizen kiln further developed and became the sole source of domestically produced jars and mortar in western Japan, including the Kinai region, and was supplied to a wide area from the Pacific coast of Kanto in the north to Okinawa in the south. From the end of the 15th century to the beginning of the 16th century, kilns that had been spread over a wide area were concentrated in three locations, the Great Western Kiln, the Great Northern Kiln, and the Great Southern Kiln, and intensive production began to take place. This phenomenon occurred not only in Hitori Bizen, but also in Seto/Mino, Tokoname, Bizen, Shigaraki, and Tanba. The Rokko Kilns are a phenomenon of the large-kiln period during the transition from the medieval to the early modern period. The production at these kilns included jars, pots, and mortar of various sizes, as well as newly added vases and bowls for serving and storing food, and an extremely wide variety of vessels such as tea bowls, tea containers, flower vases, and water jars, all of which are characteristic of Bizen as well as Shigaraki. Recently, a batch of artifacts from the ruins of a wealthy merchant’s mansion discovered at the Sanjo Shiho Jusancho site in Sakyo, Heian-kyo, clearly shows how local specialties were produced in the Momoyama period. From the Momoyama Period to the Edo Period, Bizen ware eventually shifted to the blackish-brown Ibe style, which developed from painted clay.
Tamba
Tamba ware, which originated in the mountainous western part of the Kinai region, has the brightest and most refined appearance of all the Yakishime wares. This is largely due to the color tone of the surface of the ware, which has a light green natural glaze that flows down from a grayish-white base with less iron than other medieval ceramics, and to the reliable shaping of the clay, which is highly refractory.
Tamba ware, also called Onohara ware in the old days, was fired in the mountains around Tamba Sasayama City, Hyogo Prefecture. In the past, based on numerous artifacts, I have the opinion that the origin of medieval Tamba ware does not date back to the middle of the Kamakura period, and that it was born from the Sue ware type of medieval pottery following the Sue ware of the Heian period, as in the case of Bizen ware, etc. However, the existence of ancient three-stripe jars, which cannot be considered to be from anywhere but Tamba, etc., has led me to explore the relationship between Tamba ware and Tokai ware. On the other hand, the presence of ancient sanjiki jars, which cannot be considered outside of Tamba, has led us to seek a connection with the Tokai kilns. However, the excavated artifacts from the Sanbotoge Kita Kiln excavated in 1977 clearly proved that the Tamba kiln was not of the Sue ware type, but of the Ji ware type, similar to the Tokoname and Atsumi kilns. They include a wide variety of vessels, including jars, bottles, pots, bowls, and bowls with a bright green natural glaze on a grayish-white base, many of which are decorated with a three-stripe or autumn grass design, clearly indicating the existence of a new ceramic art world that had not been expected of medieval Tamba pottery. One of the vases with an akikusa design has a similar design to a jar with an akikusa design excavated from a sutra mound behind Ishimine-ji Temple in Awakawa, Kobe, and bearing a sutra scroll inscribed in 1117, which may date back to the early 12th century.
However, the Tamba kilns, like the Tokai kilns, did not have Shirashi production in the preceding stages, and recent research has revealed that Sue ware production in the surrounding area, which was widespread, did not disappear after the Tamba kilns were established, but continued until the early Muromachi period as Sue ware medieval kilns like the Uozumi kiln in Akashi City. On the other hand, the Sue ware kiln was excavated in 1980.
On the other hand, two kilns excavated in 1980 in the Kako River basin in Nishiwaki City’s Ryokufudai Kiln Site Group have a similar structure to that of the Sue ware kilns in the Tokai region, with a dividing pillar between the combustion chamber and firing chamber, and the excavated items are similar to those from the Sanage kilns of the early 12th century. The Tamba kiln was built under the influence of the Sanage kiln. Although it is not yet possible to confirm whether the Tamba kiln is directly connected to the Ryokufudai kiln, which is located some distance away, it must be assumed that it appeared in the western Kinai region, where Sue ware kilns were widely spread, in the 12th century under the influence of the Sai ware system.
Distribution of Tamba Kilns
Tamba is one of the most representative of Japan’s medieval kilns, and although its products are well known throughout the world, the number of kiln sites known today is surprisingly small.
The Tamba kilns in the narrow sense of the term, which belong to the Middle to Early Modern period, are distributed over an area of 5 km from east to west and 5 km from north to south, from near Tachikake, Sasayama City, Hyogo Prefecture, to Yotsuji, Sanda City, in the southeast. Of these, the existence of medieval kilns is known only on the Imada-cho side. The kilns are located on the southern half of Mt. Kyokuzo (596 m above sea level), which rises on the east side of the narrow flatland in the center of Imada Town, where the Yotodani River, a tributary of the Kako River, runs through the town from north to south. Only five kilns are known to date: the Sanbon-toge Kilns (four kilns), the Tokodani Kilns (Kinbeizan), the Genbeizan Kilns, the Tarosaburo Kilns, and the Inariyama Kilns, which are distributed on the hillside at an elevation of 200 to 250 meters. Even if we include several kilns in each group, the total number of kilns is only a dozen or so. However, this is due to inadequate research, and by analogy with the vast amount of artifacts now known, there is no doubt that the number of ancient kiln sites is not as large as this. The Sanbon-toge kiln is the oldest of the five groups of kiln sites mentioned above, dating back to the late Heian period, and the Inariyama kiln is the newest, but the Monohara artifacts date back to the early Muromachi period, and no later kiln sites have yet been identified. Recently, an old kiln that fired suribachi (mortar bowls) dating back to the Muromachi Period has been discovered in the Kamaya area in the southwestern part of the basin, suggesting that the migration from the Inariyama kiln to the Kamaya kiln may have been much earlier than previously thought.
Tamba Products
The types of vessels fired at the Tamba kilns in the medieval period include bowls, plates, bowls, bottles, jars, jarred tea utensils, and many others. However, as is the case with other medieval kilns except Seto Mino, Tamba in the Middle Ages focused on three types of vessels: jars, pots, and ground bowls, with only a few other types of vessels mentioned above, and the combination of these types varies depending on the period. Of the three main types of vessels, jars are the most common, followed by pots and jars, and very few ground bowls.
There are more than seven types of jars, including round-bodied, long-bodied, flat-bodied, short-necked, wide-mouthed, shoulder-jointed, and one-mouthed jars. Of these, the two types of large jars, round-bodied and long-bodied, were the most common, and were fired throughout each period. The round-bodied jars, like paulownia-patterned jars, are slightly stout and have a large diameter in relation to their height, while the earliest types have a neck that is strongly curved outward from the shoulder, so-called “warped mouth. Long-bodied jars, such as those marked “Nunobiki” (Fig. 150), are long and narrow in relation to their height, with a warped mouth neck. Flat-bodied jars were produced in small numbers from the Nanbokucho period through the Muromachi period. Wide-mouthed jars have a large, trumpet-shaped neck, as seen in jars with chrysanthemum patterns and pottery shards excavated from the Sanbon-toge kiln, and may have been converted from wide-mouthed bottles, which are found only in early examples. Another type has a mouthpiece with the upper half of the mouth neck standing up against the outer surface. Smaller jars include katakuchi jars with a partially folded mouth rim. Shoulder jars are long-bodied jars with the shoulders bent at right angles, and appeared from the end of the Muromachi period to the Momoyama period.
Next, there are three types of Tamba jars. One is a jar with a large diameter in relation to its height, and the other is a jar with a narrow diameter. The former type is similar to Tokoname jars, and has a rim band around the mouth, while the latter has a round mouth. The latter type, which appeared somewhat later, is unique to Tamba and has a double rim. The third type, which appeared in the middle of Muromachi period (1333-1573), has a broad green band with an inner bay.
The production of suribachi was extremely small in Tamba until the Edo period, when it was shifted to the climbing kilns. The grated bowls have a single grating pattern with widely spaced inner surface, a technique that was followed until the Momoyama period (1573-1600).
In addition, tableware such as bowls, small plates, and shallow bowls were produced only in the early stages of the Edo period. The bowl is about 13 cm in diameter and 3.5 cm in height, wheel-thrown, and has a thread-cut mark on the bottom. The small dish is roughly made with a diameter of 7.6 cm and a height of around 2.6 cm. This bowl and small dish correspond to a set of mountain tea bowls and small dishes from the Tokai region.
The only bottles found in the collection are those in the form of tokkuri, which are common in the late Muromachi period. In addition, although they are few in number, oke (buckets) began to appear in the late Muromachi period.
Many of them were used as single-lobed water jars from the Momoyama period onward. In addition to the above, there are also large shallow bowls and plates that were fired in the late Momoyama period. It was excavated from the ruins of an old kiln in Kamaya, and was fired by overlaying ceramic shards in several places around the bottom of the inner surface.
Production Techniques of Tamba
In the Tamba area, granite and quartz coarse-grained rocks erupted between the Paleozoic layers are widely found and form the base layer, but the Neogene layer, which supplies high-quality pottery clay, has not been formed. The ceramic clay currently mined at Yotsuji is alluvial clay deposited on quartz coarse-grained rock, and is of rather poor quality due to its high iron content.
According to a map of the pottery site dating from the Bunroku Genna period (1688-1704), it is known that in the early period the clay was extracted from the Sanbon Dainan area, and in the medieval period it is clear that the clay was used near the ruins of the old kilns.
Next, looking at the molding technique, while small items such as bowls and plates were made by water wheel throwing, large and medium-sized items such as jars and grinders were made by winding up clay strings. First, ashes are spread over the base and a circular base is formed, then a thick clay cord is rolled up to the waist, and after drying, the clay cord is rolled up again to add more clay to the base. Once the shape was completed, the surface of the vessel was scraped to eliminate irregularities, and the wood was used horizontally to adjust the shape. After the mid-Muromachi period, however, the method of adjusting the surface of the vessel by using a coarse comb vertically, known as nekoguride, came to be adopted. The trend of decorating the surfaces of vessels in medieval Tamba began in the first half of the late Heian period (794-1185) and early Muromachi period (1333-1573). These were Atsumigama-style patterns such as those of autumn grasses and lotus petals, and in rare cases, designs of trees and paulownia vases were painted on the surface of vessels.
Although the firing techniques of the Tamba kilns are still a matter of conjecture since no kiln sites have been excavated, it is clear from the products that they are descended from the Tokoname and Atsumi kilns, and they are thought to have had a similar porcelain kiln body structure to the Nishiwaki City Ryokufudai kiln.
Changes in the Tamba Kiln
The Tamba kilns of the Middle Ages are currently known only from the end of the Heian period to the beginning of the Kamakura period to the early Muromachi period, with less than ten kiln sites at five locations. In the middle to late Muromachi period, only a few pieces are known to have been handed down. However, as mentioned earlier, the presence of a jar with an Akikusa design excavated from a sutra mound on the back of Ishimineji Temple in Kobe City clearly indicates that Tamba kilns began in the first half of the 12th century. The transition of the Tamba kiln can be divided into six periods from the late Heian period to the Momoyama period. These are: I. Late Heian to early Kamakura period, II. middle to late Kamakura period, III. late Kamakura to Nanboku-cho period, IV. early to mid Muromachi period, V. late Muromachi to late Muromachi period, and VI. the Momoyama period. The only known kiln from Period I is the Sanbontoge Kita Kiln. This kiln, which mainly produced jars and jar-ground bowls, was particularly notable for its production of jars. Looking at the form of the jar, the mouth rim and body shape are similar to those of the Atsumi Tokoname kiln. Bowls and sets of small plates are also seen, but their forms follow those of Sue ware of the previous period. Among the jars produced during this period, several are known to be distinctive in that they are warped-mouth vases with trumpet-shaped openings at the neck and shoulders decorated with autumn grasses.
Some of them, such as the jar excavated from the Sutra Mound behind Ishimine-ji Temple in Kobe, have a design similar to that of the Atsumi and Akikusa jars, while others, such as the three-mimi jar with a chrysanthemum flower design, have a superior design. Also known are medium-sized jars with three-stripe or lotus petal design on the shoulder. In the middle and late Kamakura period of Period II, bowls and small plates disappear, and the three vessel types of jars, pots, and ground bowls become more prominent. The mouth necks of wide-mouthed jars become upright and the shoulder patterns disappear. Jars and pots began to differentiate according to their function, and two types of jars were produced: round-bodied jars and long-bodied jars, or jars with thicker or thinner bodies, and jars of various sizes were produced. In particular, the double-edged mouths of jars and pots were a characteristic of this period. Jars with paulownia designs are representative of this period. The Inarizan kiln is the only kiln known today from the Nanbokucho period of the III era.
The characteristics of the jars and pots are completely different from those of the Tokoname kiln, and they have become fully Tamba. While jars of various sizes were produced, the culture of vessel forms has progressed, with the appearance of flattened round-bodied jars and small jars with one side of the mouth. In the middle and late Muromachi period (Period IV-V), there are no known kiln sites, but there are a large number of pottery objects from this period. The neck of the mouth of jars gradually became more pronounced, and the edge of the mouth changed to a jade-rim style. Jars also became unique to Tamba with horizontally bent mouth rims, while a new type with inwardly curved mouth rims was born. A major change during this period was the emergence of the cat’s cat hand and kiln marks as a method of adjusting the surface of vessels. These are thought to have been methods used in response to mass production. The Momoyama Period (Period VI) was the last stage of the Tamba cellar kilns. As seen in a jar inscribed in Keicho II, the neck of the mouth began to tilt inward, and new types of jars, large plates, and tubs appeared. Only a few mizusashi (tea utensils) were produced, but the Edo period saw a major development in the tea industry.
