[13] According to History of Northern Dynasties and Zizhi Tongjian, in 545 Tumen's tribe started to rise and frequently invaded the western frontier of Wei.

The chancellor of Western Wei, Yuwen Tai, sent An Nuopanto (安諾盤陀, Nanai-Banda, a Sogdian from Bukhara,[14]) as an emissary to the Göktürk chieftain Tumen, in an attempt to establish a commercial relationship.

Bumin got angry, killed Anagui's emissary, and severed relations with the Rouran Khaganate.

[15][17][18][19] Anagui's "blacksmith" (鍛奴 / 锻奴, Pinyin: duàn nú, Wade–Giles: tuan-nu) insult was recorded in Chinese chronicles.

[15][17][18] In the same year when Emperor Wen of Western Wei died, Bumin sent mission and gave two hundred horses.