The Kofun period, named after the keyhole-shaped tomb mounds constructed for the local elite, marked Japan’s increased contacts with the continent and its development into a unified state.

A distinctive funeral custom of burying their elite in large mounded tombs, or kofun, appeared in the protohistoric period of Japan, which is known as the Kofun period. The period is traditionally dated from 300 to 710 c.e.; however, research suggests that it may have begun as early as the latter half of the third century and ended in the late seventh century. Some scholars would date the period’s end even earlier, in 552, when Buddhism was officially introduced to Japan.

The distribution of kofun extends throughout the nation, centering on the Kinai region. Although various shapes of mounded tombs have been discovered, the keyhole-shaped burial mounds, often surrounded by moats, are notable for their enormous scale. Burial mounds had been constructed in Japan since the Paleolithic period. Square mounds appeared in western Japan early in the Yayoi period (300 b.c.e.-300 c.e.) and spread widely in the main parts of Japan during the middle Yayoi period. Moats have been discovered surrounding square burial mounds at some Yayoi sites. The distinction between the tombs of the Kofun period and earlier tombs lies primarily in the shape of the mound itself. Although a variety of mound shapes were used during the period, keyhole-shaped, mounded tombs are the dominant and defining type of the Kofun period. The significant sociopolitical and cultural meanings behind the construction of these mounds indicate a change in society as well as a change in tomb shape.

Furthermore, the mounded tombs of the Kofun period are an independent and permanent type of burial mound, occupying the space above ground level and recognizable without excavation. In the kofun burial, the remains were placed in the top of the mound, unlike the Yayoi custom of burying the dead under it. The kofun was also the place where the rites of royal succession were held, in addition to funerary and mortuary rituals. Local rulers were religiously authorized to protect their people’s lives by their magical power. The kofun therefore symbolizes the highest sociopolitical power and religious or magical power of the times. Thus, its size and shape had to be impressive, and each tomb must have been made for a single ruler.

There are three phases of the Kofun period: Early (the late third to the fourth century), Middle (the end of the fourth to the fifth century), and Late (the sixth to the seventh century). Between the phases, distinct shifts are found in the structure, dimension, number, and location of mounded tombs, burial goods, and haniwa (clay cylinders), which were placed over the surface of the mound to divide the sacred space for the dead from the outer world. The changes in these elements reflect Japan’s gradual evolution toward a unified state and its close contacts with China and Korea.

This haniwa, a terra-cotta warrior, is typical of the figurines found during the later Kofun period.

(Coribs)

The tomb mounds of the Early Kofun period developed from the burial customs of the Late Yayoi, when the deceased were buried on hills, using geographical advantage. The representative keyhole-shaped Kofun period mound was composed of a circular mound joined with a triangular one, creating a keyhole shape when viewed from above. The burial chamber, located near the top of the mound, was closed with ceiling rocks and covered by earth. One of the early tombs, Hashihaka kofun in modern-day Nara Prefecture, is dated around the late third or the beginning of the fourth century. It is the oldest massive kofun tomb yet discovered, measuring 912 feet (278 meters) in length, and it is often considered to be the origin of that type. It is also the first known tomb of a local great king, suggesting the birth of the Yamato kingdom in the Nara region. The typical burial objects found in tombs of this period, symbolizing the social status of the deceased, include bronze mirrors, ornaments made of jade, jasper, and glass, iron weapons such as swords and knives, and ceramic vessels. Such burial goods do not appear to have been provided in the case of the Hashihaka kofun; however, the excavation of specific types of cylindrical and pot-shaped haniwa, which were originally developed for ritual use in Okayama Prefecture during the Late Yayoi period, indicates an early date and use of ritual at the tomb.

In the Middle Kofun period, keyhole-shaped mounds spread widely in other parts of Japan. Kofun construction reached its peak in number and dimension during this period. By the fifth century, kofun construction moved from hillsides to flat land, where the mounds were artificially made out of earth. The moats surrounding the mounds clearly distinguish the burial mounds from other areas. In the Kinki region, kofun began to concentrate in the plains of the Ōsaka area. The Daisen kofun, also known as the Mausoleum of Emperor Nintoku, is located at Sakai, Ōsaka. Although there is no archaeological basis for the identity of the deceased, the tomb is the largest keyhole-shaped mound, measuring 1,600 feet (486 meters) in length and covering 80 acres (32 hectares). It is surrounded by three moats and accompanied by fifteen smaller tombs in which close relatives and attendants of the deceased were supposedly buried. It is estimated that about twenty thousand haniwa were placed on the surface of the mound, and illustrations of the stone chamber, drawn at the time of the mound’s collapse in 1872, record some significant burial objects including bronze armor, iron swords, and glass vessels. This huge fifth century tomb manifests the power of the imperial line.

From the latter half of the fifth century, monumental tomb mounds diminished in scale and, at the same time, mounds in clusters appeared. It became popular to abandon pit-shaft-styled stone chambers in favor of tombs with a Korean-style corridor leading to the chamber. This suggests that the tombs were being used for multiple burials, such as family burials. Also, a strong military cast to the period becomes clear. The number of horse trappings and military hardware increased in burial goods, and in addition to simple cylindrical haniwa, figure haniwa in the shapes of warriors and military shields became common. In the Imashirozuka kofun in Ōsaka, 113 enormous haniwa were placed in a regular, fencelike arrangement, with palace buildings, warriors and shrine maidens, and horses and chickens representing a scene of the central court of the early sixth century. In addition to the military equipment and horse-riding goods, the Sue ware pottery is another indicator of the influx of foreign, especially Korean, culture into Japan during this time. The pottery is often found as offering vessels in the tombs. Unlike Haji ware, which was in continual casual use from the Yayoi period, Sue ware is much more refined. The pottery found in the tombs is identical to Korean vessels, and the technology must have been brought to Japan by Korean immigrants.

Around the end of the sixth century, the keyhole-shaped mounds began to disappear nationwide, suggesting the rapid centralization of Japan. The tombs of the final stage of the Kofun period are replaced by square or round mounds and are often characterized by wall paintings in the chamber. Two especially popular mounds, Takamatsuzuka kofun (late seventh century) and Fujinoki kofun (late sixth century), both in Nara Prefecture, show strong foreign influences. The designs of cosmology and figures on the wall paintings at Takamatsuzuka suggest a direct link with Chinese and Korean tomb paintings. Elaborate gold openwork crowns and the gilt bronze rear saddle bow at Fujinoki display continental motifs including those of India and Central Asia. The Kofun period ended as the result of the intense influence of continental culture, especially Buddhism and the practice of cremation.

The Kofun period is Japan’s protohistoric period, bridging the gap between the end of the prehistoric and the opening of the new, historic Japan. The four hundred years during which these tombs were constructed manifest a revolution in sociopolitical structure, during which the nature of Japanese leaders changed from charismatic to political, aiming for the centralization of Japanese government.

• Aston, W. G. Nihongi: Chronicles of Japan from the Earliest Times to a.d. 697. Revised by Terence Barrow. Rutland, Vt.: Tuttle, 1972. A translation of Nihon Shoki, an important early chronicle, from the original Chinese and Japanese writing.
• Barnes, Gina L. Protohistoric Yamato: Archaeology of the First Japanese State. Ann Arbor: University of Michigan Press, 1988. A study of early state emergence in Nara after a long-term social change. Bibliography.
• Brown, Delmer M., ed. Ancient Japan. Volume 1 in The Cambridge History of Japan. New York: Cambridge University Press, 1988. Discusses Japan’s radical sociopolitical change between 300 b.c.e. to 784 c.e. Index and glossary.
• Kondō, Yoshirō, ed. Zenpō kō enfun Shūsei. 6 vols. Tokyo: Yamakawa Shuppansha, 1992-2000. A collection of more than forty-six hundred keyhole-shaped mound tombs. Although written in Japanese, the illustrations are good for technical studies. Bibliography and index.
• Pearson, Richard. Ancient Japan. New York: George Braziller, 1992. The lavishly illustrated catalog to accompany an exhibit at the Smithsonian Institution. The commentary is intended for nonspecialist readers, and the Kofun period is one of the eras covered.
• Piggott, Joan R. The Emergence of Japanese Kingship. Stanford, Calif.: Stanford University Press, 1997. Analyzes the political changes of the Kofun period.