 He crushed the power of the Donghu people of eastern Mongolia and Manchuria as well as the Yuezhi in the Hexi Corridor of Gansu, where his son, Jizhu, made a skull cup out of the Yuezhi king.Modu also reoccupied all the lands previously taken by the Qin general Meng Tian.Under Modu's leadership, the Xiongnu threatened the Han dynasty, almost causing Emperor Gaozu, the first Han emperor, to lose his throne in 200 BC.