Perhaps in light of the new adversarial relationship with Chen, when Northern Qi made peace overtures in fall 568, Northern Zhou accepted, and there was peace between the states for about a year, until fall 569, when Emperor Wu's brother Yuwen Xian the Prince of Qi led an army to siege Northern Qi's city of Yiyang (宜陽, in modern Luoyang, Henan) -- and for more than a year, the two states would engage in struggle for the control of Yiyang. Meanwhile, in fall 570, the Chen general Zhang Zhaoda () put siege to Jiangling, nearly capturing it, but was eventually fought off by Northern Zhou and Western Liang's joint forces.