The Battle of Bang Bo, known in China as the battle of Zhennan Pass (Chinese:鎮南關之役), was an important Chinese victory during the Sino-French War (August 1884–April 1885). The battle, fought on 23 and 24 March 1885 on the Tonkin-Guangxi border, saw the defeat of 1,500 soldiers of General François de Négrier's 2nd Brigade of the Tonkin Expeditionary Corps by a Chinese army under the command of the Guangxi military commissioner Pan Dingxin (潘鼎新).