Two secret documents signed by China’s Mao Zedong during the 1930s sold for almost a million dollars at a New York auction on Wednesday, reported the state-run news agency China News Service.

The rare documents are related to the famous 1936 Xi’an Incident, a turning point in Chinese history when one of Chiang Kai-shek’s most trusted generals, the “Young Marshal” Zhang Xueliang, placed him under house arrest — forcing the leader of the nationalist Chinese Republic of China to negotiate a cease-fire with Mao’s Communists, in order to fight a joint war against the Japanese invasion....