The predecessor of the Northern Wei dynasty, Dai Kingdom, which once governed northern China, evolved from the Tuoba Tribe. The Tuoba Tribe maintained contact and exchanges with the dynasties of Cao Wei and Western Jin that ruled central China till the period of the Dai Kingdom, and was under the influence of their political situations and diplomatic attitudes. The reason for the Tuoba Tribe contacting the Cao Wei and Western Jin dynasties was that Tuoba Liwei, the leader of the Tuoba Tribe, expanded the ruling territory to Pingcheng. Then, Wei Cao of the Jin dynasty led native people to attach themselves to Western Jin, again owing to its domestic chaos. The Tuoba Tribe had remained polite to the Cao Wei and Western Jin dynasties, opened mutual trade and dispatched troops as help in terms of foreign policies. The diplomatic attitude of Cao Wei and Western Jin towards the Tuoba Tribe evolved from passive, hostile and finally to friendly, which alienated and weakened the Tuoba Tribe at first and then earned the Tuoba Tribe titles of nobility, land and talents owing to the military assistance provided by the Tuoba Tribe. The authority and status of the leader of Tuoba Tribe tended to rise after the exchange with Cao Wei and Western Jin dynasties, while the Western Jin dynasty were under the political influence of the Tuoba Tribe.