Maritime East Asia (244–387 CE): Fragmentation, Cultural Evolution, and Regional Realignments

Between 244 CE and 387 CE, Maritime East Asia—comprising lower Primorsky Krai, the Korean Peninsula, the Japanese Archipelago below northern Hokkaido, Taiwan, and southern, central, and northeastern China—experiences profound political fragmentation, regional realignments, cultural evolution, and technological innovation following the collapse of the Han dynasty.

Fragmentation and the Rise of Regional Powers

The collapse of the Han dynasty ushers in nearly four centuries of fragmentation, beginning with the era of the Three Kingdoms (Wei, Shu, and Wu, 220–280 CE). While later romanticized for chivalry, this era is marked by widespread warfare. The brief reunification under the early Jin dynasty (265–420 CE) proves fragile, unable to withstand persistent invasions by northern nomadic groups.

Forced to flee from Luoyang in 317 CE, the Jin court relocates to Nanjing, signaling China's division into successive dynasties and kingdoms lasting until 589 CE. This period sees accelerated sinicization, as non-Chinese groups integrate culturally, notably accompanied by the spread of Buddhism, introduced in the first century CE.

Technological and Cultural Advancements

Despite political fragmentation, significant technological advancements occur. Innovations such as gunpowder(initially for fireworks), the wheelbarrow, and notable developments in medicine, astronomy, and cartography emerge during this turbulent period.

Developments in Korea: Baekje, Goguryeo, and Silla

On the Korean Peninsula, three powerful states emerge: Baekje in the southwest, Goguryeo in the north, and Silla in the southeast.

Baekje, known for its centralized aristocratic structure, emerges strongly by 246 CE, aggressively expanding northward. Its King Kun Ch'ogo (r. ca. 346–375) establishes a lasting royal succession tradition, and in 384 CE, Buddhism is officially adopted as the state religion.

Goguryeo, initially developed near the Yalu River, expands significantly, conquering the Chinese-held region of Lelang in 313 CE. Situated in rugged terrain and harsh climates, Goguryeo becomes a major regional power, heavily influencing Korean history and identity, particularly as claimed by modern North Korea.

Silla, with its capital at Kyongju, becomes known for its cultural richness. The ruling elites from Silla’s region will notably dominate South Korean political leadership in later historical periods, shaping its national historical narrative.

The Kofun Period in Japan

In Japan, the Kofun period represents a critical evolutionary stage toward state formation. Society flourishes particularly along the eastern Inland Sea, with Japanese military influence extending onto the southern Korean Peninsula. Early Japanese rulers actively seek and obtain diplomatic recognition from China. Chinese records from this period describe the Japanese (Wa) society as fragmented, yet increasingly centralized under powerful leaders like the famed queen Himiko of Yamatai, who maintains diplomatic relations with China’s Wei Dynasty (220–265 CE).

Influence of Migration: Wu Hu Tribes

The period witnesses significant migrations into China by various non-Chinese tribes collectively termed the Wu Hu (Five Hu). Initially pastoral nomads from the steppe regions, these tribes leverage the collapse of central authority to settle extensively in the fertile North China Plain, reshaping the region’s demographic and cultural landscape.

Legacy of the Age: Political Realignment and Cultural Foundations

Thus, the age from 244 to 387 CE is characterized by political fragmentation, significant cultural evolution, and regional realignments. Despite instability, this era establishes enduring cultural and political foundations, significantly influencing the historical trajectories of China, Korea, and Japan.

The Migration Period affects China as well.

Wu Hu (literally "Five Hu") is a collective term for various non-Chinese steppe tribes during the period from the Han Dynasty to the Northern Dynasties.

Their origin lies outside China proper, but they have gradually migrated into Chinese areas during the years of turmoil between the Eastern Han Dynasty and Three Kingdoms.

The Wu Hu, whom the Han had fought to a standstill, have seized the opportunity afforded by the weakness of the central government to extend their settlement of pastoral lands into the fertile North China Plain.

Jin forces have been completely driven out of North China by 317.

An attempt to recover the Central China plain under general Zu Tì is initially successful in recovering all of Henan and Shandong but ends with Zu's death in 321.

The forces of the Xiongnu “Empire” of Han Zhao, led by general Liu Yao, the Prince of Zhongshan, capture the new Jin emperor, Min, in Chang'an in 316, and the whole of north China comes under Xiongnu rule.

Remnants of the Jìn court flee south of the Chang Jiang River and reestablish the Jìn court at Jiankang, southeast of Luoyang and Chang'an and near modern-day Nanjing, under the Prince of Longya.

When the news of the fall of Chang'an reaches the south, the prominent local families of Zhu, Gan, Lu, Gu, and Zhou support the proclamation of the Prince as Emperor Yuan of the Eastern Jìn Dynasty.

(Because the emperors of the Eastern Jìn Dynasty thus spring from the Langye line, the rival Wu Hu states, which do not recognize its legitimacy, will at times refer to Jìn as "Langye.")

The Han Zhao, or Former Zhao, a state of the Sixteen Kingdoms during the Jin Dynasty, represents two state titles, the Han state proclaimed in 304 by Liu Yuan and the Former Zhao state in 319 by Liu Yao.

(The reason it is referred to as Former Zhao is that when its powerful general Shi Le breaks away and forms his own state in 319, he names it Zhao as well, and so Shi Le's state is referred to as Later Zhao.)

Although chronologically the Han Zhao is not the first of the Sixteen kingdoms, its armies had sacked the Jin dynastic capitals of Luoyang in 311 and Chang'an in 316.

Emperor Huai and Emperor Min of the Jin had been captured, humiliated and executed.

Remnants of the Jin court have fled to Jiankang, located eastward of Luoyang and Chang'an, and founded the so-called Eastern Jin Dynasty, under Sima Rui the Prince of Langye, who later becomes Emperor Yuan.

In 318, Liu Can and the ruling family residing at Pingyang had been toppled and executed by the coup d'etat of Jin Zhun, who is in turn eliminated by Shi Le and Liu Yao, who, as an imperial prince, claims the throne and changes the name of the state to Zhao.

Shi Le, of the Shi family of the Jie ethnicity, establishes Later Zhou, a state of the Sixteen Kingdoms during the Jin Dynasty, in 319.

The Later Zhao, with its capital at Xiangguo (in modern Xintai, Hebei), is the second, in territorial extent, to the Former Qin that once unified Northern China under Fu Jian.

The Zhang family of the Han Chinese ethnicity establishes Former Liang, a state of the Sixteen Kingdoms, in 320.

Its territories include present-day Gansu and parts of Ningxia, Shaanxi, Qinghai and Xinjiang.

All rulers of the Former Liang will remain largely titular under the court of the Jin dynasty as the Duke of Xiping except Zhang Zuo who proclaims himself "wang" (prince/king).

However, at times the other Former Liang rulers will also use the wang title when imposed on them when they are forced to submit to Han Zhao, Later Zhao, or, eventually, Former Qin.

Wang Dun, a Jin Dynasty general and later warlord with paramount authorities, having brought Emperor Yuan (Sima Rui) to submission with his military force, now apparently intends to seize the Jin throne by force, but grows ill in 324 and dies as Emperor Ming is repelling his forces.

The rebellion of Jin Dynasty general Su Jun against Emperor Cheng's regent Yu Liang is initially successful, allowing him to take over the imperial government.