During the Song Dynasty, there were many threats from the northern borders by the Khitans (å¥ä¸¹) from the Liao Dynasty (é¼å½), Tanguts from the Western Xia (西å¤) Dynasty, and the Jurchens (女ç) from the Jin dynasty (éå½).
The reason was that Qinzong, the last emperor of the Northern Song was living in Jin-imposed exile in Manchuria and had a good chance of being recalled to the throne should the Jin Dynasty be destroyed.
Emperor Wányán Lià ng failed in taking the Song and was assassinated by his own generals in December of 1161.