However, impressed with Pú Jiàn's bravery, archery, horsemanship, and generosity, Shi Hu favored him greatly and spared him.
In 349, as Shi Hu was gravely ill, he commissioned Pu Hong to be the governor of Yong Province (雍州, modern central and northern Shaanxi).
However, it appeared that Pu Hong did not immediately proceed to his post, but was slow in preparing his Di troops for assignment while at his base at Fangtou (枋頭, in modern Hebi, Henan).
As the turmoil continued, the Di and Qiang whom Shi Hu had previously forced to move to eastern China began to disregard Later Zhao's laws and seek to return to their ancestral homes in the west.
Both armies advanced west quickly, and in winter 350, Chang'an fell to Fu Jian's forces.
He soon declared himself the "Heavenly King" (Tian Wang), formally breaking from Jin (and Later Zhao) and establishing Former Qin.
He continued to engage both former Later Zhao generals who controlled small fiefdoms and Former Yan and Jin forces, as the three states settled their borders by force in the aftermaths of Later Zhao's final destruction in 351 and the subsequent fall of Ran Min (formerly known as Shi Min) to Former Yan in 352.
In 354, the Jin general Huan Wen launched a major attack on Former Qin, in coordination with Former Liang forces.