He Helped Zhu Di Claim The Throne As Yongle Emperor
When Emperor Zhu Yuanzhang passed away, Zhu Di was the emperor's eldest surviving son because his older brothers had all perished young. But Zhu Di's nephew, the crown prince's son, succeeded his uncle as Jianwen Emperor and made an effort to contain his uncle's influence. Zhu Di fought back and launched an offensive against his nephew.
Ma He was one of the commanders in charge of this operation, which finally resulted in Zhu Di's ascension to the position of Yongle Emperor in 1402 Ma He was a crucial campaign strategist as well.