After the fall of Zhao, Qin turned its attention towards Yan. Crown Prince Dan of Yan sent Jing Ke to assassinate Ying Zheng but the assassination attempt failed and Qin used that as an excuse to attack Yan. Yan lost to Qin at a battle on the eastern bank of the Yi River in 226 BC and King Xi of Yan fled with remnant forces to Liaodong. Qin attacked Yan again in 222 BC and annexed Yan completely. In 225 BC, the Qin army led by Wang Ben invaded Wei and besieged Wei's capital city of Daliang for three months. Wang directed the waters from the Yellow River and the Hong Canal to flood Daliang and King Jia of Wei surrendered and Wei was conquered.