魏太武帝
In 448 the Emperor Taiwu of Northern Wei received an envoy from the Yueban to negotiate a war with the Rouran. If the Yueban would pressure them from the west, the Rouran would lose any freedom to maneuver. Though no direct records exist about the war in Dzungaria, by the course of the events, there was no peace, and the nomadic empire of Rouran began to decline.