The rebels now besiege Zuo Chang's headquarters…

Emperor Mingyuan sends one of his advisors, Baba Song the Duke of Nanping, to attack the Rouran, in 410 and when Baba is surrounded by Rouran troops, Emperor Mingyuan personally leads an army to relieve Baba.

Yujiulü Hulü, who had begun his rule over the Rouran in May 410, offers a tribute in the following year of three thousand horses to the Han Chinese Northern Yan ruler Feng Ba, with a request to marry Feng Ba's daughter, Princess Lelang, who is probably the daughter of Feng Ba's wife, Princess Sun.

Feng Ba's brother, Feng Sufu, suggests refusing the request and sending the daughter of one of Feng Ba's concubines instead, but Feng Ba is apparently convinced that an alliance with Rouran would be beneficial to his state, and agrees to give Princess Lelang in marriage to Yujiulü Hulü.

The khagan Yujiulü Hulü, in 414, the fourth year of his rule over the Rouran, is about to oversee the marriage of one of his own daughters to Feng Ba when he is overthrown by his nephew Yujiulü Buluzhen, who, along with the coup leaders, sends Yujiulü Hulü and his daughter to Northern Yan.

Feng Ba treats him as an honored guest and, as originally planned, takes Yujiulü's daughter as a concubine.

Yujiulü Hulü requests that Feng Ba send an army to escort him home and, in May 414, Feng Ba, with some reluctance, gives him an escort commanded by general Wan Ling who, according to the account, returns after having killed Yujiulü Hulü along the way.