Maritime East Asia (100–243 CE): Decline of Han Dynasty and Increasing Turbulence

Between 100 CE and 243 CE, Maritime East Asia—comprising lower Primorsky Krai, the Korean Peninsula, the Japanese Archipelago below northern Hokkaido, Taiwan, and southern, central, and northeastern China—faces mounting internal struggles, administrative breakdown, and rebellions that mark the decline and eventual collapse of the Han dynasty.

Continued Han Rule and Increasing Strains

After a brief interruption by Wang Mang's Xin Dynasty (9–24 CE), the Han dynasty had been restored and continues for nearly two centuries more. However, the restored Han rulers struggle to manage a vastly expanded population, increasing economic wealth paired with financial instability, and increasingly complex bureaucratic and political institutions. Administrative corruption spreads widely, a classic symptom of dynastic decline.

Peasant and Taoist Rebellions

Persistent dissatisfaction among peasants leads to widespread agrarian rebellions, exacerbating the empire's instability. Taoist-inspired movements, notably the Yellow Turban Rebellion, challenge Han authority, advocating egalitarian ideals and drawing massive popular support, further weakening imperial governance and draining critical resources from central authority.

Fragmentation and Collapse

The cumulative effect of internal corruption, administrative inefficiency, and recurrent rebellions severely undermines the Han dynasty's stability. By 220 CE, the Han Empire formally collapses, fragmenting into several competing states. This collapse ushers in the Three Kingdoms Period, profoundly altering China's political and social landscape for centuries.

Legacy of the Age: Transition and Fragmentation

Thus, the age from 100 to 243 CE is characterized by mounting administrative strain, widespread popular discontent, and internal rebellions culminating in the definitive collapse of the Han dynasty. These events set the stage for a prolonged period of fragmentation, warfare, and eventual reorganization that reshapes East Asian political dynamics.

The Three Kingdoms period in Chinese history is part of an era of disunity called the Six Dynasties following immediately the loss of de facto power of the Han Dynasty emperors.

In a strict academic sense, it refers to the period between the foundation of the Wei in 220 and the conquest of the Wu by the Jin Dynasty in 280.

Many scholars extend the starting point of this period back to the uprising of the Yellow Turbans in 184.

The three kingdoms are Wei, Shu, and Wu.

Zhuge Liang's Southern Campaign, also known as the War of Pacification in Nanzhong, is a military campaign led by Shu Han chancellor Zhuge Liang to suppress opposing forces in the South in 225.

The campaign is a response to rebellions started by local governors in the southern region of Nanzhong and intrusions by the Nanman (literally: "southern barbarians").

Zhuge Liang's Northern Expeditions are a series of five military campaigns launched by the state of Shu Han against the rival state of Cao Wei from 228.

China’s Later Han Dynasty collapses by 221, due largely to economic woes and intense political factionalism at court.

Massive peasant rebellion and the resulting dissolution of the empire lead to the so-called Period of Disunion.

A series of semi-Sinicized barbarian peoples rule North China; Chinese colonial regimes settle the south.

Three separate kingdoms replace the empire (in what later historians will call the “Three Kingdoms” period.)

Confucianism is discredited and aristocrats, rather than the Confucian-tested morally superior men, dominate the governments.

Fierce racial tension and great physical destruction ensues.

The nomadic Turkic-speaking bandits known as the Xiongnu (Hsiung-nu), based in Mongolia, begin to threaten China’s borders.

Liu Bei declares himself emperor as well, establishing Shu Han, after news of Cao Pi's ascension (and an accompanying false rumor that Cao had executed Emperor Xian) arrives in Liu Bei's domain of Yi Province (modern Sichuan and Chongqing).

Sun Quan, who controls the vast majority of modern southeastern and southern China, takes no affirmative steps one way or another, leaving his options open.

An armed conflict between Liu and Sun quickly develops, because in 219, Sun Quan's general Lü Meng had invaded and annexed Liu Bei's territory in Jing Province (modern Hubei and Hunan).

Guan Yu, the general appointed by Liu Bei to defend Jing Province, had been captured after his defeat and executed on Sun Quan's order.

Liu Bei was enraged by the sudden attack because Sun Quan was formerly his ally, and also due to his close relationship with Guan Yu.

Liu now wants to take vengeance on Sun for Guan Yu's death.

Many of his subjects, including Zhao Yun, oppose his decision, but Liu Bei ignores them.

As Liu Bei mobilized his troops in preparation for the attack on Sun Quan, another of his generals, Zhang Fei, is growing impatient with the preparations for war, so he imposes strict deadlines on his subordinates Fan Qiang and Zhang Da, but his subordinates fail to meet the time limit.

Zhang Fei disparages them before warning them that they will be executed under military law if they founder again.

Out of fear, Fan Qiang and Zhang Da kill Zhang Fei while he is asleep, cut off his head, and defect to Sun Quan.

Liu Bei is overwhelmed with grief over the loss of two of his generals, who had accompanied him since the beginning of his military career.

Zhang Fei's death hardens his decision to attack Wu for revenge.

Again, many Shu officials attempt to dissuade Liu Bei from attacking Sun Quan, but Liu dismisses their advice.

Eventually, Liu Bei departs from his capital, Chengdu, with a large army and advances towards Jing Province on both land and water (along the Yangtze River).

He leaves his chancellor Zhuge Liang and crown prince Liu Shan to defend Chengdu.

Sun, to avoid having to fight on two fronts, formally pays allegiance to Cao, offering to be a vassal of Cao Wei.

Cao's strategist Liu Ye suggests that Cao decline and instead attack Sun on a second front, which would effectively partition Sun's domain with Shu Han, and would eventually allow Cao to destroy Shu Han as well.

Such an opportunity will not come again.

Cao declines this suggestion, a fateful choice that most historians believe doomed his empire to ruling only northern and central China.

Indeed, against Liu Ye's advice, he creates Sun the Prince of Wu and grants him the nine bestowments.

Sun Quan’s forces, due to their superiority in numbers, initially underestimate the enemy's tenacity.

As the advancing Shu army captures regions including Zigui, Wu County, Mount Ba and Mount Xing, Sun Quan’s forces that set out from their fortifications to engage the enemy are nearly all annihilated.

The initial defeat causes Sun Quan to decide to adopt Lu Xun's strategy and appoint Lu as Grand Viceroy (de facto commander-in-chief of Sun Quan's forces).

Sun Quan’s forces, realizing that the Shu troops are better versed in warfare in mountainous terrain as they are mostly ground troops, decide to abandon their defenses at certain territories and retreat to vital positions and defend them instead.

After this, they intend to hold on to these positions and wait for an opportunity to launch a counterattack.

Shu naval forces led by Wu Ban and Chen Shi capture Yiling in January 222.

Liu Bei builds his headquarters in Zigui but does not stay there for long as his forces continue to make progress and push further into the heartland of Sun Quan’s territories.

The Shu vanguard breaks through enemy lines at Yidao in February and defeats Sun Quan’s defenders in an engagement outside the city.

Sun Quan’s general Sun Huan, who is guarding Yidao, retreats with his remaining troops into the city and holds on to his position until a stalemate is reached.

The main Shu force led by Liu Bei  meanwhile reaches Xiaoting and is unable to push any further as Sun Quan’s forces led by Lu Xun hold on firmly to their positions.

With no further retreat by Sun Quan’s forces, both sides reach a stalemate at Xiaoting.

As Shu troops venture further into Sun Quan’s territory, their supply lines from Chengdu lengthen and supplies take longer to arrive.

They also become gradually weary and tired from battle.

The terrain becomes flatter and the Shu infantry loses the advantage the had held in mountainous terrain.

Liu Bei deploys his troops in over fifty camps along the three hundred and fifty-kilometer line from Wuxia to Yiling on the southern bank of the Yangtze River.

His vanguard army is isolated one hundred and fifty kilometers away at Yidao.

Sun Quan’s forces think that this the best time to launch their counterattack, but Lu Xun orders them to hold on.

Most of Sun Quan’s forces had evacuated by March from mountainous terrain to fortifications on flatland.

Summer soon arrives and the sweltering heat kills several plants and shrubs.

Liu Bei's forces camped at Yiling are directly next to a forest and the heat becomes even more unbearable.

Some Shu soldiers are affected by heatstroke.

By now, the Shu army's morale has fallen significantly as compared to at the start of the campaign, as the troops are now weary and suffering from the intense heat.

Liu Bei deploys eight thousand elite troops to lie in ambush in nearby valleys and sends Wu Ban to lead a weaker force to challenge and lure Sun Quan’s forces out of their fortifications into the ambush.

However, Lu Xun sees through Liu Bei's ruse and orders his troops to ignore taunts from the enemy.

It is said that he even ordered his troops to put wax into their ears.

The failure of the ambush causes the Shu army's morale to plummet even lower.

Shu troops are suffering from the summer heat as the stalemate, which had begun in March, continues.

Liu Bei decides to shift his camp into the nearby forest for shade and shelter from the heat even though his adviser Ma Liang opposes his decision.