Yulin's strategic location on the northern frontier made it a contested zone for millennia. The area was on the border between agricultural China and the nomadic steppes, with the Great Wall running through its territory.
In 413 AD, the Hunnic leader Helian Bobo established the Xia Kingdom and built Tongwan City as his capital. The city, whose name means "ruling ten thousand states," was a remarkable achievement of nomadic urban planning. It served as the Xia capital until 427 AD when it was conquered by the Northern Wei.
During the Tang Dynasty, the region was administered as part of the frontier defense system. The famous poet Wang Wei wrote about the desolate beauty of the northern frontier during this period.
The Ming Dynasty (1368-1644) marked Yulin's greatest era of military importance. As one of the "Nine Garrisons" (Jiubian), Yulin was heavily fortified with walls, towers, and a permanent military garrison. Zhenbei Tower was built in 1607 as the crowning defensive structure.
The city also played a role in the fall of the Ming Dynasty. Li Zicheng, the peasant rebel who briefly established the Shun Dynasty, was born in Mizhi County near Yulin in 1606. His rebellion would eventually lead to the collapse of Ming rule.
In modern times, Yulin has transformed from a military frontier to an energy production center, with coal and natural gas fields discovered in the region.