 Abaoji , who later became Emperor Taizu of Liao , was born in 872 , the son of the chief of the Yila tribe . At that time , the Yila tribe was the largest and strongest of the eight affiliated Khitan tribes ; however , the Great Khan , the overall leader of the Khitans , was drawn from the Yaolian lineage . In 901 Abaoji was elected to be the chief of the Yila tribe by its tribal council . By 903 , Abaoji had been named the <unk> , the overall military leader of the Khitans , subordinate only to the Great Khan . Four years later , in 907 , Abaoji became the Great Khan of the Khitans , ending nine generations of Yaolian rule . Abaoji acquired the prestige needed to secure the position of Khitan Great Khan through a combination of effective diplomacy and a series of successful military campaigns , beginning in 901 , against the Han Chinese forces to the south , the Xi and <unk> to the west , and the Jurchens in the east . 
