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History of Japan
Daisen-Kofun, the tomb of Emperor Nintoku in Osaka, one of the Mozu kofungun
Periods Paleolithic 35,000–14,000 BC Jōmon 14,000–1000 BC Yayoi 1000 BC – 300 AD Kofun 300–538 AD Asuka 538–710 Nara 710–794 Heian Former Nine Years' War Later Three-Year War Genpei War 794–1185 Kamakura Jōkyū War Mongol invasions Genkō War Kenmu Restoration 1185–1333 Muromachi Nanboku-chō period Sengoku period 1336–1573 Azuchi–Momoyama Nanban trade Imjin War Battle of Sekigahara 1573–1603 Edo (Tokugawa) Tokugawa shogunate Invasion of Ryukyu Siege of Osaka Sakoku Perry Expedition Convention of Kanagawa Bakumatsu Meiji Restoration Boshin War 1603–1868 Meiji Ryūkyū Disposition Invasion of Taiwan (1874) Satsuma Rebellion First Sino-Japanese War Treaty of Shimonoseki Triple Intervention Invasion of Taiwan (1895) Colonization of Taiwan Boxer Rebellion Russo-Japanese War Treaty of Portsmouth Japan–Korea Treaty Colonization of Korea 1868–1912 Taishō World War I Intervention in Siberia Great Kantō earthquake 1912–1926 Shōwa Militarism Financial crisis Nanking incident Mukden Incident Invasion of Manchuria May 15 incident February 26 incident Anti-Comintern Pact Tripartite Pact Second Sino-Japanese War World War II Attack on Pearl Harbor Pacific War Atomic bombings Soviet–Japanese War Surrender of Japan Occupation of Japan Postwar Japan Anpo protests Economic miracle Asset price bubble 1926–1989 Heisei Lost Decades Great Hanshin earthquake Cool Japan Tōhoku earthquake Imperial transition 1989–2019 Reiwa COVID-19 pandemic Abe assassination Noto earthquake 2019–present
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Glossary History Timeline

The Kofun period (古墳時代, Kofun jidai) is an era in the history of Japan from about 300 to 538 AD (the date of the introduction of Buddhism), following the Yayoi period. The Kofun and the subsequent Asuka periods are sometimes collectively called the Yamato period. This period is the earliest era of recorded history in Japan, but studies depend heavily on archaeology since the chronology of historical sources tends to be distorted. The word kofun is Japanese for the type of burial mound dating from this era.

It was a period of cultural import. Continuing from the Yayoi period, the Kofun period is characterized by influence from China and the Korean Peninsula; archaeologists consider it a shared culture across the southern Korean Peninsula, Kyūshū and Honshū.^[1] On the other hand, the most prosperous keyhole-shaped burial mounds in Japan during this period were approximately 5,000 in Japan from the middle of the 3rd century in the Yayoi period to the 7th century in the Asuka period, and many of them had huge tombs,^[2][3] but in the southern Korean Peninsula there were only 13 from the 5th century to the 6th century, and the tombs were small. Wall decorations and Japanese-style armor, which are characteristic of older Japanese burial mounds, were excavated from 5th century burial mounds in the southern Korean Peninsula. This shows that Japan and the southern Korean Peninsula influenced each other.^[4][5]

According to the Nihon Shoki, Buddhism and the Chinese writing system were introduced near the end of the period from Baekje. The Kofun period recorded Japan's earliest political centralization, when the Yamato clan rose to power in southwestern Japan, established the Imperial House, and helped control trade routes across the region.^[6]

Kofun (from Middle Chinese kú 古 "ancient" + bjun 墳 "burial mound")^[7][8] are burial mounds built for members of the ruling class from the 3rd to the 7th centuries in Japan,^[9] and the Kofun period takes its name from the distinctive earthen mounds. The mounds contained large stone burial chambers, and some are surrounded by moats.

Kofun have four basic shapes: round and square are the most common, followed by 'scallop-shell' and 'keyhole.' The keyhole tomb is a distinct style found only in Japan, with a square front and round back. Kofun range in size from several meters to over 400 meters long, and unglazed pottery figures (Haniwa) were often buried under a kofun's circumference.

The oldest Japanese kofun is reportedly Hokenoyama Kofun in Sakurai, Nara, which dates to the late 3rd century. In the Makimuku district of Sakurai, later keyhole kofuns (Hashihaka Kofun, Shibuya Mukaiyama Kofun) were built during the early 4th century. The keyhole kofun spread from Yamato to Kawachi—with giant kofun, such as Daisenryō Kofun—and then throughout the country during the 5th century. Keyhole kofun disappeared later in the 6th century, probably because of the drastic reformation of the Yamato court; Nihon Shoki records the introduction of Buddhism at this time. The last two great kofun are the 190-metre-long (620 ft) Imashirozuka kofun in Osaka (currently believed by scholars to be the tomb of Emperor Keitai) and the 135-metre long (443 ft) Iwatoyama kofun in Fukuoka, recorded in Fudoki of Chikugo as the tomb of Iwai (political archrival of Emperor Keitai). Kofun burial mounds on the island of Tanegashima and two very old Shinto shrines on the island of Yakushima suggest that these islands were the southern boundary of the Yamato state;^[6] it extended north to Tainai in the present-day Niigata Prefecture, where excavated mounds have been associated with a person closely linked to the Yamato kingdom.^[10]

Yamato rule is usually believed to have begun about 250 AD, and it is generally agreed that Yamato rulers had keyhole-kofun culture and hegemony in Yamato until the 4th century. Autonomy of local powers remained throughout the period, particularly in Kibi (the present-day Okayama Prefecture), Izumo (current Shimane Prefecture), Koshi (current Fukui and Niigata Prefecture), Kenu (northern Kantō), Chikushi (northern Kyūshū), and Hi (central Kyūshū). During the 6th century, the Yamato clans began to dominate the southern half of Japan. According to the Book of Song, Yamato relationships with China probably began in the late 4th century.

The Yamato polity, which emerged by the late 5th century, was distinguished by powerful clans (豪族, gōzoku). Each clan was headed by a patriarch (氏上, Uji-no-kami), who performed sacred rituals to the clan's kami (objects of worship) to ensure its long-term welfare. Clan members were the aristocracy, and the royal line which controlled the Yamato court was at its zenith. Clan leaders were awarded kabane, inherited titles denoting rank and political standing which replaced family names.

The Kofun period is called the Yamato period by some Western scholars, since this local chieftainship became the imperial dynasty at the end of the period. However, the Yamato clan ruled just one polity among others during the Kofun era. Japanese archaeologists emphasise that other regional chieftainships (such as Kibi) were in close contention for dominance in the first half of the Kofun period; Kibi's Tsukuriyama Kofun is Japan's fourth-largest.

The Yamato court exercised power over clans in Kyūshū and Honshū, bestowing titles (some hereditary) on clan chieftains. The Yamato name became synonymous with Japan as Yamato rulers suppressed other clans and acquired agricultural land. Based on Chinese models (including the adoption of the Chinese written language), they began to develop a central administration and an imperial court attended by subordinate clan chieftains with no permanent capital. Powerful clans were the Soga, Katsuragi, Heguri and Koze clans in the Yamato and Bizen Provinces and the Kibi clans in the Izumo Province. The Ōtomo and Mononobe clans were military leaders, and the Nakatomi and Inbe clans handled rituals. The Soga clan provided the government's chief minister, the Ōtomo and Mononobe clans provided secondary ministers, and provincial leaders were called kuni no miyatsuko. Craftsmen were organized into guilds.

In addition to archaeological findings indicating a local monarchy in Kibi Province as an important rival, the legend of the 4th-century Prince Yamato Takeru alludes to the borders of the Yamato and battlegrounds in the region; a frontier was near the later Izumo Province (eastern present-day Shimane Prefecture). Another frontier, in Kyūshū, was apparently north of present-day Kumamoto Prefecture. According to the legend, there was an eastern land in Honshū "whose people disobeyed the imperial court" and against whom Yamato Takeru was sent to fight.^{[citation needed]} It is unclear if the rival country was near the Yamato nucleus or further away. Kai Province is mentioned as a location where prince Yamato Takeru traveled on his military expedition.

The period's northern frontier was explained in Kojiki as the legend of Shido Shōgun's (四道将軍, "Shōguns to four ways") expedition. One of four shōguns, Ōbiko set out northward to Koshi and his son Take Nunakawawake left for the eastern states. The father moved east from northern Koshi, and the son moved north;^{[contradictory]} they met at Aizu, in present-day western Fukushima Prefecture. Although the legend is probably not factual, Aizu is near southern Tōhoku (the northern extent of late-4th-century keyhole-kofun culture).

During the Kofun period, an aristocratic society with militaristic rulers developed. The period was a critical stage in Japan's evolution into a cohesive, recognized state. The society was most developed in the Kinai region and the eastern Setouchi region. Japan's rulers petitioned the Chinese court for confirmation of royal titles.

While the rulers' title was officially "King", they called themselves "Ōkimi" (大王, "Great King") during this period. Inscriptions on two swords (the Inariyama and Eta Funayama Swords) read Amenoshita Shiroshimesu (治天下; "ruling Heaven and Earth") and Ōkimi, indicating that the rulers invoked the Mandate of Heaven. The title Amenoshita Shiroshimesu Ōkimi was used until the 7th century, when it was replaced by Tennō.

Many of the clans and local chieftains who made up the Yamato polity claimed descent from the imperial family or kami. Archaeological evidence for the clans is found on the Inariyama Sword, on which the bearer recorded the names of his ancestors to claim descent from Ōbiko (大彦, recorded in the Nihon Shoki as a son of Emperor Kōgen). A number of clans claimed origin in China or the Korean Peninsula.

During the 5th century, the Katsuragi clan (葛城氏, descended from the legendary grandson of Emperor Kōgen) was the most prominent power in the court and intermarried with the imperial family. After the clan declined, late in the century, it was replaced by the Ōtomo clan. When Emperor Buretsu died with no apparent heir, Ōtomo no Kanamura recommended Emperor Keitai (a distant imperial relative in Koshi Province) as the new monarch. Kanamura resigned due to the failure of his diplomatic policies, and the court was controlled by the Mononobe and Soga clans at the beginning of the Asuka period.

Toraijin refers to people who immigrated to Japan from abroad via the Ryukyu Islands or the Korean Peninsula. They introduced numerous, significant aspects of Chinese culture to Japan such as Chinese writing system and Buddhism from India. Valuing their knowledge and culture, the Yamato government gave preferential treatment to toraijin.^[11] According to the 815 book, Shinsen Shōjiroku, 317 of 1,182 clans in the Kinai region of Honshū were considered to have foreign ancestry. 163 were of Chinese origin (written as "Kan"), 104 from Baekje ("Paekche" in the older romanization), 41 from Goguryeo, 6 from Silla, and 3 from Gaya.^[12] They may have immigrated to Japan between 356 and 645.

Some of the many immigrants that had significant influence in Kofun period Japan included Wani, Yuzuki no Kimi and Achi no Omi, the founders of Kawachinofumi clan/Kawachinoaya clan,^[13] Hata clan^[14][15] and Yamatonoaya clan,^[16][17] respectively. Despite being ethnically similar, many immigrants from Baekje and Silla had arrived in Japan during Emperor Ōjin's reign carrying separate identities and foreign deities such as the kami Inari.^[18][19]

Other immigrants who settled in Japan beginning in the 4th century were the progenitors of Japanese clans. According to Kojiki and Nihon Shoki, the oldest record of a Silla immigrant is Amenohiboko: a legendary prince of Silla who settled in Japan at the era of Emperor Suinin, possibly during the 3rd or 4th centuries.

Baekje and Silla sent their princes as hostages to the Yamato court in exchange for military support.^{[20][21][22][23]} King Muryeong of Baekje was born in Kyushu (筑紫) of Japan as the child of a hostage in 462,^[24] and left a son in Japan who was an ancestor of the minor-noble Yamato no Fubito (和史, "Scribes of Yamato") clan. According to the Shoku Nihongi (続日本紀), Yamato no Fubito's relative (Takano no Niigasa) was a 10th-generation descendant of King Muryeong of Baekje who was chosen as a concubine for Emperor Kōnin and was the mother of Emperor Kanmu. In 2001, Emperor Akihito confirmed his ancient royal Korean heritage through Emperor Kanmu.^[25]

Chinese, Japanese, and Koreans wrote historical accounts primarily in Chinese characters, making original pronunciation difficult to trace. Although writing was largely unknown to the indigenous Japanese of the period, the literary skills of foreigners seem to have been increasingly appreciated by the Japanese elite. The Inariyama Sword, tentatively dated to 471 or 531, contains a Chinese-character inscription in a style used in China at the time.^[26]

The cavalry wore armour, carried swords and other weapons, and used advanced military methods similar to those of Northeast Asia. Evidence of the advances is seen in haniwa (埴輪, "clay ring"), clay offerings placed in a ring on and around the tomb mounds of the ruling elite. The most important of these haniwa were found in southern Honshū (especially the Kinai region around Nara Prefecture) and northern Kyūshū. Haniwa grave offerings were sculpted as horses, chickens, birds, fans, fish, houses, weapons, shields, sunshades, pillows, and male and female humans. Another funerary piece, the magatama (勾玉, "curved jewel"), became symbolic of imperial power.

Much of the material culture of the Kofun period demonstrates that Japan was in close political and economic contact with continental Asia (especially with the southern dynasties of China) via the Korean Peninsula; bronze mirrors cast from the same mould have been found on both sides of the Tsushima Strait. Irrigation, sericulture, and weaving were brought to Japan by immigrants, who are mentioned in ancient Japanese histories; the Hata clan introduced sericulture and certain types of weaving.^[27]

The introduction of Buddhism in 538 marked the transition from the Kofun to the Asuka period, which coincided with the reunification of China under the Sui dynasty later in the century. Japan became deeply influenced by Chinese culture, adding a cultural context to the religious distinction between the periods.

According to the Book of Sui, Silla and Baekje greatly valued relations with the Kofun-period Wa and the Korean kingdoms made diplomatic efforts to maintain their good standing with the Japanese.^[28] The Book of Song reported that a Chinese emperor appointed the five kings of Wa in 451 to supervise military affairs of Wa, Silla, Imna, Gara, Jinhan and Mahan.^[29]

According to the Nihon Shoki, Silla was conquered by the Japanese Empress-consort Jingū in the third century.^[30] However, due to lack of evidence,^[31] this story is considered to be mythological in nature. It reported that the prince of Silla came to Japan to serve the emperor of Japan,^[32] and lived in Tajima Province. Known as Amenohiboko, his descendant is Tajima Mori.^[33] According to Kojiki^[34] and Nihon Shoki,^[35] Geunchogo of Baekje presented stallions, broodmares and trainers to the Japanese emperor during Emperor Ōjin's reign.^[36]

According to Kojiki and Nihon Shoki, Baekje had also sent a scholar by the name of Wani during the reign of Emperor Ōjin. He is said to be the pioneer of the introduction of the Chinese writing system to Japan.

The Samguk sagi (Chronicles of the Three Kingdoms) reported that Baekje and Silla sent their princes as hostages to the Yamato court in exchange for military support to continue their military campaigns; King Asin of Baekje sent his son (Jeonji) in 397,^[37] and King Silseong of Silla sent his son Misaheun in 402.^[38] Hogong, from Japan, helped to found Silla.^[39]

In 2021, a research paper proposed a new theory as to the origins of the Japanese people. It suggested that the people of Japan bore genetic signatures from three ancient populations rather than just two as previously thought.^[40] The paper called this strand the "Kofun strand" based on the samples found in the period, and separated it from the pre-existing "Jōmon" and "Yayoi strand" forming the "Tripartite ancestry theory".^[40]

However recently, the tripartite ancestry theory is being met with criticism since its introduction in 2021. In essence, Japanese researchers claim that a tripartite theory is redundant as the genetical difference between Yayoi and Kofun groups is not significant enough and that the temporal discrepancy of the periods is minuscule. See Japanese people's Tripartite ancestry theory.

Under an agreement reached at the 2001 Japan-South Korea summit, Japanese and South Korean historians conducted joint historical research in two phases, including the relationship between Japan and the Korean Peninsula during the Kofun period. The point at issue was the "Mimana Nihon-fu" (任那日本府) which was said to be the governing institution Japan established in Korea at that time. After the controversy, Japanese and South Korean historians agreed that there were Japanese in the south of Korea and that the term "Mimana Nihon-fu" was not used at the time and should not be used as it was misleading. However, they could not agree on the position of the Japanese people in Korea at that time. The Japanese side claimed that the institutions established in Korea by the Japanese people were not under the control of Koreans, but were operated independently by the Japanese people and conducted diplomatic negotiations with the Gaya confederacy. On the other hand, the South Korean side claimed that the agency was the diplomatic office of Gaya, which employed the Japanese as bureaucrats of Gaya. The collaboration ended in 2010 with the publication of a final report describing the above. The full text of the minutes concerning the joint research is disclosed by the Japanese side.^{[41][42][43][44][45]}

• 
  Kofun helmet, iron and gilt copper
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  Kofun Tankō (short armor)
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  Kofun Keikō (cuirass)
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  Helmet
• 
  Shield
• 
  Crown
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  Restored Kofun period lamellar armour

• Japanese clans
• Kuni no miyatsuko
• Kumaso
• Kofun
• Kofun system
• Zenpokoenfun

• Bogucki, Peter (1999). The Origins of Human Society. Blackwell Publishing. ISBN 1-57718-112-3.
• Farris, William Wayne (1998). Sacred Texts and Buried Treasures: Issues in the Historical Archaeology of Ancient Japan. University of Hawai'i Press. ISBN 0-8248-1966-7.
• Imamura, Keiji (1996). Prehistoric Japan: New Perspectives on Insular East Asia. University of Hawaii Press. ISBN 0-8248-1852-0.
• Kōzō, Yamamura; John Whitney Hall (1997). The Cambridge history of Japan. Cambridge University Press. ISBN 0-521-22354-7.
• Kurano, Kenji; Yūkichi Takeda (1958). Nihon Koten Bungaku Taikei 1: Kojiki, Norito. Iwanami Shoten. ISBN 4-00-060001-X.
• Saeki, Arikiyo (1981). Shinsen Shōjiroku no Kenkyū (Honbun hen) (in Japanese). Yoshikawa Kōbunkan. ISBN 4-642-02109-4.
• Sakamoto, Tarō; Ienaga Saburō; Inoue Mitsusada; Ōno Susumu (1967). Nihon Koten Bungaku Taikei 67: Nihon Shoki. Vol. 1. Iwanami Shoten. ISBN 4-00-060067-2.
• Seeley, Christopher (2000). A history of writing in Japan. University of Hawai'i Press. ISBN 0-8248-2217-X.
• Stearns, Peter N.; William Leonard Langer (2001). The Encyclopedia of World History. Houghton Mifflin Harcourt. ISBN 0-395-65237-5.
• Yamaguchi, Yoshinori; Kōnoshi Takamitsu (1997). Shinpen Nihon Koten Bungaku Zenshū 1: Kojiki. Shōgakukan. ISBN 4-09-658001-5.
• Yoshida, Takashi (1997). Nihon no tanjō (in Japanese). Iwanami Shoten. ISBN 4-00-430510-1.
• This article incorporates text from this source, which is in the public domain. Country Studies. Federal Research Division.
• Japan

• Mizoguchi, Kaoji (2013). The Archaeology of Japan: From the Earliest Rice Farming Villages to the Rise of the State. Cambridge University Press.