Yongle Emperor
The Jianwen Emperor's many uncles were very powerful, almost like kings. He started to take away their power right away. One was sent away to Yunnan, one killed himself, three were made into common people. Zhu Di was afraid and pretended to be crazy. The Jianwen Emperor was less afraid of him and even let Zhu Di's three sons—whom he held in Yingtian (now Nanjing) to be sure of Zhu Di's good behavior—go to Beiping (now Beijing) to visit their "sick" father before his death.