Later Yan forces were led by its crown prince Murong Bao and enjoyed some initial successes, but after being frustrated by the containment strategy of the Northern Wei ruler Tuoba Gui (Emperor Daowu), withdrew.

[6][7] After Former Qin suffered a major defeat against Jin forces at the Battle of Fei River in 383 in a failed bid to unite China, it began to disintegrate, and, among others, Later Yan, with Murong Chui, the uncle of Former Yan's last emperor Murong Wei, as emperor (Emperor Wucheng), took over Former Yan's old territory and people; and Northern Wei, with Tuoba Shiyiqian's grandson Tuoba Gui[8] as prince, took over Dai's former territory and people.

Early in his reign, Tuoba Gui had often met opposition from powerful individuals within his own state, and had to rely on Later Yan's aid to quell the rebellions.

[10] Despite his planning, however, he continued joint operations with Later Yan, and in 390 and 391, he and Murong Lin defeated the Helan (賀蘭), Hetulin (紇突鄰), and Hexi (紇奚) tribes together.

Tuoba Gui agreed, and he sent his troops and livestock far to the west away from his capital Shengle (盛樂, in modern Hohhot, Inner Mongolia), crossing the Yellow River into the Ordos Desert.

Meanwhile, Later Yan forces advanced to Wuyuan (五原, in modern Baotou, Inner Mongolia), receiving the surrender of some 30,000 households who were Northern Wei vassals.

Later Yan forces then built Fort Hei (黑城), north of Wuyuan, and began to build boats to cross the Yellow River.

The Later Qin emperor Yao Xing launched a relief force commanded by the general Yang Fosong (楊佛嵩).

The sorcerer Jin An (靳安), serving Murong Bao, claimed to foresee disaster and suggested an immediate retreat.

[11] At that time, there were blocks of ice on the Yellow River, but it was not fully frozen, and therefore Murong Bao did not believe that Northern Wei forces could cross easily.

When Later Yan forces reached Canhe Slope (in modern Liangcheng),[13] the army became enveloped in darkness, probably due to the storm.

However, when his army arrived at Canhe Slope, he offered sacrifices to the deceased soldiers—and his own soldiers, many of whom had relatives who died, cried bitterly.

Tuoba Gui almost immediately launched a major attack, and in 397, Murong Bao was forced to abandon Zhongshan and retreat back to the old Former Yan capital Longcheng (龍城, a.k.a.