Competing with the Xiongnu for supremacy were the
Donghu people () and the
Yuezhi. In 215 BCE,
Qin Shi Huang, the founding emperor of the
Qin dynasty, sent a 300,000-man army headed by General
Meng Tian into the
Ordos region and
drove the Xiongnu northward for 1,000 , or about . "Touman, unable to hold out against the Qin forces, had withdrawn to the far north, where he held out for over ten years." After the death of Meng Tian in 210 BCE, Touman led the Xiongnu across the
Yellow River to regain their previous territory. A legend says that Touman favoured a younger son from another concubine. To get rid of his eldest son,
Modu, Touman sent him to the Yuezhi as a hostage and then made a sudden attack on them. In retaliation, the Yuezhi prepared to kill Modu, but he managed to steal a horse and escape back to the Xiongnu. Touman was impressed by his bravery and put Modu in command of a force of 10,000 horsemen. Modu was very successful in training and his men obeyed him absolutely. In 209 BCE, Modu commanded his men to shoot his father, killing him as well as his stepmother, younger brother, and high officials who refused to take orders from him. Thereafter, Modu became . ==Footnotes==