Before the end of the Han Dynasty, the warlord Ma Teng commanded a sizable army in the northwestern frontiers of China that threatened the North China Plain controlled by Cao Cao. When Cao Cao finished his unification of northern China in 207, he wished to turn south to attack Liu Bei and Sun Quan; so to avoid being attacked from behind, Cao Cao appointed Ma Teng as an official and summoned him to Ye City. Ma Teng and some of his family members were effectively held hostage to prevent Ma Teng's son, Ma Chao, from invading Cao Cao's territory.