In 257 BC, Qin was still unable to penetrate Handan after besieging it for three years, and Zhao requested aid from the neighbouring states of Wei and Chu. Wei was hesitant to help Zhao initially, but launched an attack on Qin after seeing that Qin was already exhausted after years of war. The Qin forces crumbled and retreated and Zheng Anping surrendered. The combined forces of Wei and Chu continued to pursue the retreating Qin army and Wei managed to retake part of its original lands that were lost to Qin earlier.