The Tumultuous Rise of the Jurchen

In the winter of 1116 AD, a rebellion erupted in the Liao Dynasty’s eastern capital of Liaoyang that would dramatically alter the balance of power in Northeast Asia. The uprising, led by a disgruntled Bohai official named Gao Yongchang, exposed the crumbling foundations of Khitan rule and created an opportunity that the Jurchen chieftain Wanyan Aguda (known as Akuta in some records) would exploit with ruthless efficiency.

The Bohai people, descendants of the ancient Mohe tribes, had long chafed under Liao rule. When Gao and his followers assassinated the oppressive Liao governor Xiao Baoxian on New Year’s Day, it sparked widespread revolt across the Liaodong region. Within days, Gao declared himself emperor of a restored Bohai state, controlling over fifty prefectures. This sudden collapse of Liao authority in its wealthiest northeastern territories presented Aguda with an irresistible opportunity.

The Jurchen Gambit

Aguda’s Jurchen forces, based in the northern Manchurian plains (modern Jilin and Heilongjiang), had previously been unable to penetrate the prosperous southern regions of Liaoning. The Bohai rebellion changed everything. When Gao Yongchang requested Jurchen assistance against Liao counterattacks, Aguda dispatched troops under his general Zemu – not to aid the rebels, but to conquer territory for himself.

The Jurchen capture of Shenzhou (modern Shenyang) in May 1116 marked a turning point. Rather than supporting Gao, Aguda’s forces turned on their supposed allies, crushing the Bohai rebellion and absorbing its territories. This demonstrated the Jurchen leader’s strategic vision – he sought not temporary alliances, but permanent conquest.

Song Dynasty’s Calculated Response

News of the Jurchen victories reached the Song court, where hawkish factions saw an opportunity to reclaim the long-lost Sixteen Prefectures. In 1117, military commander Tong Guan was recalled from the northwest to prepare northern defenses. However, Emperor Huizong’s extravagant projects – including the construction of the Genyue imperial garden – strained Song finances, forcing controversial tax reforms that increased peasant burdens.

The emperor hesitated when reports suggested possible Liao military movements near the border. After sending an investigative mission that found no evidence of imminent Liao attack, Huizong temporarily shelved military plans. Yet the idea of a Jurchen alliance continued to simmer.

The Diplomatic Dance

In 1118, the Song initiated contact through a daring maritime mission led by Ma Zheng. After being detained by suspicious Jurchen guards, Ma’s delegation finally met Aguda at his camp along the Lailiu River. The Jurchen leader, simultaneously negotiating with Liao envoys seeking to recognize him as “Emperor of the Eastern Humble State,” recognized the strategic value of a Song alliance.

Aguda’s demands to the Liao were intentionally impossible – requiring the Khitan emperor to address him as elder brother and cede vast territories. With the Song, however, he proved more accommodating. When Zhao Liangshi (a former Liao official serving the Song) arrived in 1120 to formalize the alliance, Aguda agreed in principle to return the Yanjing (Beijing) and Xijing (Datong) regions to Song control after joint conquest.

The Contentious Terms

The resulting “Alliance Conducted at Sea” contained several critical provisions that would later cause conflict:

1. Military Coordination: Both sides would attack simultaneously in 1121 – the Song targeting Yanjing from the south, the Jurchen attacking from the north.

2. Territorial Division: The Jurchen would receive lands north of the Yan Mountains while the Song reclaimed the Sixteen Prefectures.

3. Financial Terms: The Song would transfer its annual tribute to the Liao (200,000 taels of silver and 300,000 bolts of silk) to the Jurchen.

4. Non-Negotiation Clause: Neither party would make separate peace with the Liao.

However, ambiguous wording about implementation and differing interpretations of the agreement’s conditions planted seeds for future discord.

Cultural and Strategic Miscalculations

The Song court fatally misjudged both their Jurchen allies and Khitan opponents. Officials like An Yaochen warned that destroying the Liao would remove a buffer state, exposing the Song directly to the more militant Jurchen. Others noted the Jurchen’s “wolf-like” nature compared to the sinicized Khitans.

Meanwhile, the Jurchen recognized the Song’s military weakness during their joint assault on the Liao capital in 1122. When Song forces failed to take Yanjing without Jurchen assistance, it emboldened Aguda’s successors to demand greater concessions.

The Alliance’s Collapse and Consequences

After the Liao’s fall in 1125, disputes over territory (particularly the Ping, Ying, and Luan prefectures) and tribute payments led to open conflict. The Jurchen, now ruling as the Jin Dynasty, invaded Song territory in 1126, culminating in the catastrophic Jingkang Incident and the fall of Kaifeng the following year.

The failed alliance demonstrated the perils of short-term strategic thinking. The Song’s eagerness to reclaim lost territories blinded them to the emerging Jurchen threat, while the Jurchen’s initial willingness to negotiate gave way to expansionist ambitions once Liao resistance collapsed. The episode marked a pivotal transition in East Asian geopolitics, ending the centuries-old balance between Chinese and steppe powers and ushering in a new era of Jurchen dominance.

Legacy of a Fateful Decision

The Song-Jin alliance represents one of history’s most consequential diplomatic miscalculations. For the Song, it brought about the loss of northern China and the establishment of the Southern Song rump state. For the Jurchen, it provided the springboard to establish one of China’s most powerful conquest dynasties. The complex interplay of ethnic tensions, military calculations, and cultural misunderstandings during these negotiations offers enduring lessons about the unpredictable consequences of geopolitical realignment.