It commands the narrowest choke point in the strategic Liaoxi Corridor, a crucial coastal landway between the North and Northeast China.

It is located in Shanhaiguan District, Qinhuangdao, Hebei province, on the east bank of the Shi River between the Yan Mountains and the coast of Liaodong Bay.

Throughout Chinese history, the pass served as a frontline defensive outpost against ethnic groups from Northeast China (Manchuria), including the Khitan and Jurchen (Manchus).

[4] Located south of Yan Mountain, and north of the Bohai Sea, for centuries the pass guarded the narrow passage between Northeast and Central East China.

[5] In 1381, Ming general Xu Da and his soldiers were ordered to repair the old Yongping (永平) and Jieling (界岭) passes.

During the Qianlong Emperor's reign under the Qing dynasty, Shanhai Pass became the seat of Linyu County (临榆县城) under the jurisdiction of Yongping Mansion (永平府).

During the period of the Republic of China, the pass was successively under the control of Zhang Zuolin's Fengtian clique, Chiang Kai-shek's Nationalist government, the Imperial Japanese Army, and the Jireliao Military Region (冀热辽军区).

The pass formed the southern limit of the Russian sphere of influence as defined in the convention between Great Britain and Russia of the 28th of April 1899.

"In July 1900, 15,000 Imperial Japanese Army troops landed at Shanhai Pass as part of the Eight-Nation Alliance, prior to marching on Beijing to relieve the Siege of the International Legations by the Boxers.

[8] In November 1945, the North Eastern People's Liberation Army (PLA) attempted to hold Shanhaiguan against Kuomintang forces attacking from the south.

Later, after the Communist Party began to gain the upper hand in the Chinese Civil War, the city became a destination for refugees fleeing the Liaoshen campaign.

After occupying the capital, Li attempted to enlist the support of Ming general Wu Sangui, commander of the powerful Ningyuan garrison north of the Great Wall.