Yan Border Defense

Guardians of the northern frontier holding the line against chaos and nomads.

via Wikipedia: Yan (state) · see source

The State of Yan stood as the northernmost power among the Warring States, its core territory centered around modern Beijing and Hebei, stretching from the northern frontier near the Yalu River to the Liaodong Peninsula. Facing constant incursions from steppe nomads, Yan constructed great walls to secure its borders while maintaining a reputation for sincerity and courage among the Central Plains states. Although often viewed with low regard by southern kingdoms like Qi and Zhao, Yan survived until 222 BC, falling just one year before Qin's total conquest of China in 221 BC. Its history is marked by strategic resilience, though it was never revived as a continuation of the original entity after the Qin collapse.

Lore & Background

Yan's military identity was forged by its geography and the threat of steppe nomads. During the Warring States period, General Qin Kai launched campaigns against the Donghu and Gojoseon, expanding frontiers roughly 300-400 kilometers east to the northwestern Korean Peninsula. To defend these new borders, Yan built a Great Wall and established five commanderies: Shanggu, Yuyang, Youbeiping, Liaoxi, and Liaodong. The state's culture reflected this hybrid existence; archaeological finds show ornaments with Chinese writing but nomadic styles, and their currency was shaped like knives, likely designed for trade with northern tribes. Strategically, Yan's defensive formations were solid but lacked flexibility. As recorded in The Book of Master Wu, the people were sincere and straightforward, loving courage and righteousness while rarely employing deception. This made them excel in defense but immobile, prompting enemies to use small attacks and rapid retreats to create anxiety within their ranks.

Reader's Guide

Yan's strategic value lies in its northern position, bordering the rivals Zhao and Qi to the south and facing nomadic threats to the north. The mountainous western border with Zhao was a frequent clash point, though wars between them often ended in stalemate requiring outside mediation. In 227 BC, as Qin crushed Zhao, Crown Prince Dan sent assassin Jing Ke to kill the King of Qin (later Qin Shi Huang) in Xianyang. The mission failed; Jing Ke died at the King's hands. Enraged, the Qin king ordered Wang Jian to destroy Yan. After crushing the bulk of the Yan army at the frozen Yi River, Ji fell the following year, forcing King Xi to flee to Liaodong. By 222 BC, Liaodong also fell, marking Yan as the third-to-last state conquered by Qin. In the post-Qin interregnum starting in 207 BC, Han Guang was appointed King of Yan but refused a demotion to Liaodong and was killed by General Zang Tu, who then ruled until rebelling against the new Han dynasty.

Did You Know?

The currency of Yan was crafted into the shape of a knife, a form closely associated with northern nomads and likely used for trade with them.
In 314 BC, Qi invaded Yan during a succession crisis and practically conquered the country in just several months before being driven out by a revolt.
Yan fell in 222 BC, making it the third-to-last state to be conquered by Qin, dying just one year before the declaration of the Qin Empire in 221 BC.