Jinzhou (Chin-chou) Liaoning China

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.

Emperor Mingyuan launches a major attack on Northern Yan in 418, and puts the Northern Yan capital Helong (in modern Jinzhou, Liaoning) under siege, but is unable to capture Helong and forced to retreat.

Feng Hong tries to appease the Northern Wei emperor by delivering gifts of beef and wine to his army but to no avail.

Ten Northern Yan prefectures surrender to Northern Wei, and Northern Wei forces capture a number of Northern Yan cities and put Helong under siege.

However, two months later, Emperor Taiwu withdraws at the start of winter, after capturing thirty thousand households from Northern Yan and relocating them to his You Province (modern Beijing, Tianjin, and northern Hebei).

Feng Hong's official Guo Yuan suggests to Feng Hong that he offer to be a Northern Wei vassal and send a daughter to be Emperor Taiwu's consort, but Feng Hong refuses, stating that the enmity between the states is so deep that he will be killed anyway even if he surrenders.

(While Northern Wei was investing Helong, the Northern Wei general Zhu Xiuzhi, who had been captured from Liu Song, plotted to assassinate Emperor Taiwu and then join Feng Hong, but his plot was discovered, and he flees to Feng Hong, who in turn sends him back to Liu Song, seeking Liu Song aid.

Henceforth, Liu Song and Northern Yan will be informal allies, although Liu Song will provide little actual help.)

Feng Hong, in order to try to get Liu Song aid, sends a messenger in spring 435 to the Liu Song capital Jiankang to submit as a vassal.

Emperor Wen of Liu Song creates Feng Hong the Prince of Yan, but is unable to provide substantial aid.

Feng Hong now sends his general Tang Zhu to offer tribute to Northern Wei, and claiming illness as the reason that Feng Wangren is not coming.

This reason appears to have been rejected by Northern Wei, and Feng Hong again tries to seek Liu Song aid, but none is forthcoming.

In summer 435, Emperor Taiwu's brother Tuoba Pi, the Prince of Leping again arrives at Helong, and Feng Hong tries to appease him by offering cattle, wine, and armor, but Tuoba Pi's assistant general Qutu Yuan accuses Feng Hong of not sending hostages, and they seize six thousand Northern Yan men and women before withdrawing.

The entire Northern Yan state is by this point not significantly larger than the city of Helong itself, and it is weary of repeated Northern Wei attacks.

Feng Hong's general Yang Min suggests Feng Hong send Feng Wangren as a hostage but Feng Hong refused, instead considering a plan to evacuate his people to his ally Goguryeo.

Yang believes Goguryeo to be undependable but Feng Hong, not to be deterred, sends messengers to Goguryeo seeking aid and an agreement to harbor evacuees.

Yuan, taking advantage of Nurhaci's death, reoccupies Jinzhou, which is further north of Ningyuan.

The Imperial Ming army adopts the same strategy of developing Jinzhou into another military stronghold.