Later Qin
Following the death of the Later Qin Emperor Yao Xin, Liu Yu attacked the state of Later Qin, which controlled the valuable lands of Guanzhong, lands which had once housed the capital of the Qin, Han and Jin dynasties before the barbarian uprisings. After defeating the Later Qin army in several battles, as well as an army of Northern Wei troops which had crossed to assist the Later Qin, Liu Yu recaptured the vital cities of Chang'an and Luoyang, the former capitals of the Jin Empire. It is recorded that he engaged the Wei army by the use of spears launched by crossbows, panicking the Wei cavalry and allowing him to score a decisive victory.