May 25, 1644

Battle of Shanhai Pass

Wu Sangui commits to Qing cooperation as armies converge on Shanhai Pass

Wu Sangui's soldiers sewed white patches onto the backs of their armour, so that Qing cavalry could tell them from the Chinese troops they were about to fight.

A bargain, not an alliance

A detailed scholarly reconstruction places Wu Sangui's commitment to Qing cooperation with Prince-Regent Dorgon around 25 May 1644, two days before the Battle of Shanhai Pass.

Dorgon made Qing military assistance conditional on Wu's submission, so this was not an agreement between equal Ming and Qing partners. Li Zicheng's Shun army was deploying near the fortress on 25 May, confronting Wu's former Ming troops from the west.

Three days, not one

The detailed scholarly sequence separates the steps the listing compresses. The commitment came around 25 May; on 26 May Wu adopted Manchu signs — cutting his hair in the Manchu style — and prepared identifying white cloth; the three armies fought on 27 May.

A literal claim that Wu opened the gates on 25 May is not supported by that sequence. Popular summaries variously give 22 or 25 May, folding negotiation, passage and battle into a single event.

What happened at the pass

Shanhai Pass sits about 150 miles east of Beijing, where the Great Wall reaches the sea. On 27 May Wu's troops attacked first and were badly weakened before Dorgon committed Qing cavalry against Li's flank, producing a Shun defeat.

Dorgon then advanced on Beijing and entered it on 5 June. The famous story that Wu changed sides chiefly because Li's men seized his concubine Chen Yuanyuan is a conventional narrative that scholars treat cautiously rather than as a secure motive.

Sources

Researched 23 Aug 2026 5 sources 2 audit passes Date disputed

How this was checked

Researched from the web into a fact sheet, rewritten from that sheet, then audited against it by a different model. How the pipeline works →

Date disputed. Sources disagree about when this happened.

What the sources leave uncertain

The listed date conflates several steps. Detailed scholarly narratives place the alliance or submission commitment around 25 May, Wu’s Manchu hairstyle and white-cloth preparations on 26 May, and the formal surrender and decisive battle on 27 May.
A literal claim that Wu “opened the gates” on 25 May is not supported by the best detailed sequence consulted. Popular summaries variously give 22 or 25 May, often compressing negotiation, passage and battle into one event.