Yodong Fortress

The fortress at Yodong was built in Manchuria near the modern city of Liaoyang, China. The region was contested territory between the northern Korean Kingdom of Goguryeo and the various imperial dynasties of China.[1] The two political forces competed with each-other over trade and influence in the area by constructing fortresses in strategic locations.[2]

Yodong fortress was established prior to the year 612, possibly as early as 397.[3] The fortress was considered to be a formidable defensive obstacle as it was located near the strategically important Liao River. The fortress protected the roads leading into Korea and the nearby Goguryeo cities of Yodong and Baegam. One source refers to the fortress as the anchor of the Korean kingdom's border defense.[1] The fortress was well-stocked with provisions and maintained a large complement of troops in case of a siege.[3]

In 598 Goguryeo launched an attack across the Liao river against the newly-risen Sui dynasty. The Chinese retaliated in 612 by launching a massive retaliatory attack into Goguryeo territory, laying siege to Yodong fortress. The fortresses' defenders refused to surrender and successfully held off the Sui army. Frustrated by the invasion's lack of progress, one third of the Sui army disengaged itself from the siege and marched on the Goguryeo capital of Pyongyang. The Sui army would later be destroyed at the pivotal Battle of Salsu; the war continued until 614, but the battle effectively ending the Goguryeo–Sui War in favor of Goguryeo.[1]

Following the conflict with the Sui dynasty, Goguryeo strengthened its border defenses in preparation for a future war with the Chinese. This war came when in 642 the Tang Dynasty invaded Goguryea, successfully breaching the latter's border defenses. Yodong fortress, which was garrisoned with 10,000 soldiers and holding 40,000 civilians, held off the Tang army for some time, but an army sent to relieve the fortress was destroyed.[3][4] The Tang were able to breach the fortress walls with a rapid cavalry assault, and Yodong was eventually captured and its inhabitants enslaved.[4][5][1] Emperor Taizong of Tang would later intercede and offer freedom to the prisoners and the fortress was incorporated into a new Imperial prefecture.[5] However, the Tang unsuccessfully besieged Ansi and were forced to retreat into Northern China.[1]

The Goguryeo kingdom eventually collapsed, after which the Tang dynasty established a garrison at Yodong in 676.[2]

• List of Goguryeo fortresses in China