In 407, Northern Wei and Later Qin entered into a peace treaty, returning previously captured generals to each other. This would have a disastrous consequence on Later Qin, however, as Liu Bobo, then a Later Qin general, became angry because his father Liu Weichen had been killed by Northern Wei, and therefore rebelled, establishing his own state Xia. However, he spent much more of his energy conducting guerilla warfare against Later Qin, gradually sapping Later Qin's strength, and did not actually conduct warfare against Northern Wei.