Initially, the Mongols pretty much ruled over China as bandits, sucking out as much wealth as they could. But Kublai Khan slowly adopted Chinese political structures and political theories. In particular, Kublai Khan built a strong central government in order to cement his authority as a foreign ruler over China. During the T'ang dynasty, the Emperor had slowly become an absolute ruler; Kublai Khan finished that process and made the Emperorship absolutely autocratic.