Fall of Balhae

Overview

The fall of Balhae was the event in which, in the first month of 926, Yelü Abaoji, Taizu of the Khitan (Liao), surrounded Hanhan Castle (Upper Capital Yongchun Prefecture), the capital of Balhae, and received the surrender of its last king, Dae Insun. The capital fell little more than a month after the Khitan army set out, and Balhae, which had lasted about 230 years since its founding in 698, came to an end.

The dates in this article are the lunar dates recorded in the basic annals of the Liaoshi, converted to the solar calendar. The original dates are: proclamation of the campaign on the 16th day of the 12th lunar month of 925; siege of Fuyu Prefecture on the 29th day of the intercalary 12th month; capture of Fuyu Prefecture on the 3rd day of the first lunar month of 926; siege of Hanhan Castle on the 9th day; request for surrender on the 12th day; and formal surrender on the 14th day.

Background

Growth of the Khitan

The Khitan, who arose in the basin of the Xilamuren River in northern Liaoxi, expanded rapidly under Yelü Abaoji, who took the title Dahan in 907 and declared himself emperor in 916. In 908 the Khitan built a long wall at Jindong Haigou, apparently at the mouth of the Liao River, and began advancing into Liaodong. In 919 they remodeled the old Liaoyang Castle into Dongping Commandery and used it as a forward base for attacks on Balhae. In 924 Balhae attacked the Khitan's Yao Prefecture, killed its governor Zhang Xushi, and carried off its inhabitants, resisting the Khitan.

Balhae's diplomacy and internal troubles

Dae Insun secretly concluded alliances with Silla and others, sent envoys repeatedly to the Later Liang and Japan, and sought to counter the Khitan in coordination with the Yuchi and others. However, Silla, divided into the Later Three Kingdoms, was in no position to help. The Liaoshi lists Silla among those rewarded immediately after Balhae's fall, and some interpret this as meaning that Silla sided with the Khitan or at least watched without keeping its alliance.

Internal conditions were also poor. The Liaoshi records that the Khitan moved while taking advantage of the "disaffection" (離心) of Balhae's people. Groups that had been under Balhae's rule, including Bolou, Heishui, and Dagu, broke away, attacked Silla, surrendered to Goryeo, or paid tribute to Central Plains dynasties, and these events concentrated in 918 to 925. On the 6th and 10th of the 9th month and the 29th day of the 12th month of 925 (all lunar), senior officials such as the Minister of Rites, the Minister of Works, and the Chief Secretary, along with people of royal surname, led groups of 500 persons, 100 households, and 1,000 households to defect to Goryeo.

Course of events

In the 9th month of 925, after returning from a western campaign, Yelü Abaoji issued an edict on the 16th day of the 12th month proclaiming an attack on Balhae, and set out in person with the empress, Crown Prince Yelü Bei, and the grand marshal Yelü Yaogu (later Emperor Taizong). The records that the Huihu, Silla, Tubo, Tanghang, Shiwei, Sata, Wugu, and others also participated symbolically in the campaign. The Khitan sacrificed on Mount Muye on the 4th day of the intercalary 12th month, and on the 14th day they sacrificed a blue ox and a white horse to heaven and earth at Mount Wu and reviewed the army. On the 21st day, at Mount Salgai, they shot the "ghost arrow" to announce the departure. On the last day of that year, the 29th, they reached Shangling and at night surrounded Fuyu Prefecture (in the area of present-day Nong'an, Jilin Province), Balhae's key western stronghold. They had covered more than a thousand in nine days.