In December 1232 a.d., a single arrow changed the course of history. Loosed by a Buddhist monk, the missile struck down the leader of the second Mongol invasion of Korea. His death precipitated a lifting of the siege of Cheoin and subsequent Mongol withdrawal from Goryeo. Yet they wouldn’t be gone for long. The extended nightmare that characterized Mongol attempts to subdue the Korean kingdom was destined to continue for a generation.
The geopolitical environment of Northeast Asia in the early 13th century would be recognizable to us today. Multiple, militarized states in a relatively compact area shared diplomatic, military, and trade relations. However, the identity of the regional powerhouses at the time is different from our modern construct.
China was divided. In 1127 a confederation of Jurchen tribes had seized control of northern China, later known as Manchuria. To their south, the Jurchen faced what remained of the Chinese Song Dynasty, known today as the Southern Song. The Jurchen proclaimed the establishment of a “Great Jin” Dynasty. Fighting with the Chinese continued until a line of unassailable fortified Song cities along the Huai River forced a stalemate. This resulted in a cessation of Jin-Song hostilities in 1138 and the formalization of a new border.
The war between the Jurchen and the Chinese couldn’t have come at a worse time. In 1206, far to their north, an aggressive and ambitious Mongol chieftain was declared Khagan, Emperor of the Mongols. Genghis Khan—whose name meant “Universal Ruler”—wasted no time in turning the energy of the newly-unified Mongol and allied steppe tribes toward external foes.
Genghis Khan launched his invasion of the Jin Empire in 1211 and, by 1215, he’d taken the capital at Zhongdu (modern Beijing). Distracted by events further to the west, Genghis Khan left a force to keep the pressure on the Jin while he himself marched off to destroy the Qara Khitai (in central Asia north of the Indian subcontinent) in 1217. He then smashed the prosperous Khwarezmid Empire (a Muslim empire that included present-day Iran, Afghanistan and central Asia) in 1221.
Genghis Khan in 1229. When Ogedai led an army back to Jin lands the following year, his veteran troops made short work of the remaining resistance. Aizong, the last Jin emperor, hanged himself to avoid capture, ending that dynasty in 1234. Having toppled the Jin Empire, the conquerors would soon turn their attention to the Song.
