The Tumu Crisis, also known as the Crisis of the Tumu Fortress, or the Jisi Incident, was a border conflict between the Oirat Mongols and the Ming dynasty. In July 1449, Esen Taishi, leader of the Oir

Yu Qian, courtesy name Tingyi, art name Jie'an, was a Chinese official who served under the Ming dynasty. Under Emperor Yingzong, he worked in the Ministry of War, eventually becoming a vice minister.