Yayoi period Most of the tombs of chiefs in the
Yayoi period were square-shaped mounds surrounded by ditches. The most notable example in the late Yayoi period is
Tatetsuki Mound Tomb in
Kurashiki, Okayama. The mound is about 45 metres wide and 5 metres high and has a shaft chamber. Broken pieces of
Tokushu-kidai, cylindrical earthenware, were excavated around the mound. Another prevalent type of Yayoi period tomb is the
Yosumi tosshutsugata funkyūbo, a square mound with protruding corners. These tombs were built in the
San'in region, a coastal area off the Sea of Japan. Unearthed articles indicate the existence of alliances between native tribes in the region.
Early Kofun period One of the first keyhole-shaped kofun was built in the area, the southeastern part of the Nara Basin.
Hashihaka Kofun, which was built in the middle of the 3rd century AD, is 280 metres long and 30 metres high. Its scale is obviously different from previous Yayoi tombs. During the next three decades, about 10 kofun were built in the area. They are now known as the
Makimuku Kofun Group. A wooden coffin was placed on the bottom of a shaft, and the surrounding walls were built up by flat stones. Finally, megalithic stones formed the roof.
Bronze mirrors, iron swords,
magatama, clay vessels and other artifacts were found in good condition in undisturbed tombs. Some scholars assume that the person buried in the
Hashihaka kofun was the shadowy ancient Queen
Himiko of
Yamataikoku, mentioned in Chinese historical texts. According to these texts, Japan was called
Wa, and was a confederation of numerous small tribes or countries. The construction of gigantic kofun was the result of the relatively centralized governmental structure in the Nara Basin, possibly the origin of the Yamato polity and the Imperial lineage of Japan.
Mid-Kofun period During the 5th century AD, the construction of keyhole kofun began in
Yamato Province; continued in Kawachi, where gigantic kofun, such as
Daisen Kofun of the
Emperor Nintoku, were built; and then throughout the country. The proliferation of keyhole kofun is generally assumed to be evidence of the Yamato court's expansion in this age. However, some argue that it simply shows the spread of culture based on progress in distribution, and has little to do with a political breakthrough. A few tombs from the mid-Baekje era were excavated around the Yeongsan River basin in South Korea. The design of these tombs are notably different. The tombs that were discovered on the Korean peninsula were built between the 5th and 6th centuries CE. There remain questions about who were buried in these tombs such as nobility, aristocracy, warriors or mercenaries. File:CG Gosashi Kofun 1 7p.jpg|An example of keyhole-shaped mound in the
Early Kofun period which was drawn in
3DCG.(
Gosashi Kofun (
Nara, Nara), 4th century) File:CG Nakatsuyama kofun Southeast.jpg|An example of keyhole-shaped mound in the
Mid-Kofun period which was drawn in 3DCG.( (
Fujiidera, Osaka), 5th century) File:CG Danpusan Kofun 6 7p.jpg|An example of keyhole-shaped mound in the
Late Kofun period which was drawn in 3DCG(
Danpusan Kofun (
Nagoya), 6th century)
Late Kofun period Keyhole-shaped kofun disappeared in the late 6th century AD, probably due to the drastic reformation in the Yamato court. records the introduction of
Buddhism during this era, which led to
cremation becoming the primary funerary means of the nobility., said to be the tomb of
Soga no Umako,
Asuka,
Nara Prefecture (7th century) ==Types==