Tongguan or Tong Pass, was a former mountain pass and fortress located south of the confluence of the
Wei and
Yellow Rivers, in today's
Tongguan County,
Shaanxi, China. It was an important chokepoint, protecting
Xi'an and the surrounding
Guanzhong region from the
North China Plain. Tong Pass was built in 196 AD by the warlord
Cao Cao during the late
Han dynasty. The fortress was the seat of Tongguan County, but was demolished in the 1950s to make way for the
Sanmenxia Dam and reservoir.
History
Chinese civilization first grew up along the
Wei,
Luo, and
Yellow River valleys of the
Loess Plateau before expanding out into the "
barbarians regions. The
state of
Qin fortified the
Hangu Pass to the east of Tongguan as its eastern border and it continued to protect the Chinese heartland from outside attack during the
Qin and
Handynasties. During the
Eastern Han that succeeded
Wang Mang's short-lived "
Xin dynasty", the guards at Hangu reversed themselves and protected
Luoyang in the plains from attacks coming from the west. From the time of the
AD 211 Battle of Tongguan, however, Tongguan replaced the Hangu Pass as the principal strategic post between the
Guanzhong area and the North China Plain. Under the
Tang, the fall of Tongguan to
An Lushan's
rebels led directly to their capture of the capital
Chang'an (now
Xi'an,
Shaanxi).[2]