In October 663 ce, at the decisive Battle of Baekgang, a historical era ended in bloody fashion. At the mouth of the Keum River, a combined Korean-Chinese force soundly defeated a Korean-Japanese one in a momentous event that had profound effects upon the region for the next millennium. The unlikely conclusion to over 400 years of Korea’s division into three separate, perennially warring kingdoms, was now visible on the horizon.
The story of Korea’s Three Kingdoms—Goguryeo, Baekje, and Silla—cannot be told without placing it in context within the wider East Asian historical continuum. The first centralized government beyond the city-state level on the Korean Peninsula was Gojoseon, or “Old Joseon.” This near-legendary early Korean civilization established by the 4th Century BCE reportedly stretched from the Liao River in the north to modern Pyongyang in the south. It was both neighbor and potential rival to both the Chinese Ch’in and subsequent Han dynasties, fast consolidating power to the west.
In 194 BCE, Wiman Joseon emerged as a kingdom stretching north from modern Seoul to the Yalu River, with its capital at Wanggeom near Pyongyang. Established at a time of aggressive expansion by Han China, Wiman Joseon received material support from the Han to secure China’s northeastern border against the Manchurian Yemaeks. Chinese funds were used to help the nascent Korean kingdom expand control east and south into the peninsula. Growing in power, the kingdom’s ruler, King Ungo, provoked the Han through cross-border raids along the Yalu. This resulted in the first documented Chinese invasion of Korea in 109 BCE, a two-pronged combined operation over land and sea that set