Zhengtong Emperor
The Mongols held the Zhengtong Emperor for ransom. However, this scheme was foiled once the emperor's younger brother assumed the throne as the Jingtai Emperor (r. 1449–1457); the Mongols were also repelled once the Jingtai Emperor's confidant and defense minister Yu Qian (1398–1457) gained control of the Ming armed forces. Holding the Zhengtong Emperor in captivity was a useless bargaining chip by the Mongols as long as another sat on his throne, so they released him back into Ming China. The Zhengtong Emperor was placed under house arrest in the palace until the coup against the Jingtai Emperor in 1457, which is known as the "Wresting the Gate Incident". The Zhengtong Emperor retook the throne as the Tianshun Emperor (r. 1457–1464).