In the 7th century, Buddhism was introduced into Tibet from inland China and Nepal. During the Tubo Dynasty, Buddhist monasteries and monks were supported and administered by royal families. From the end of the 10th century to the middle of the 11th century, Tibetan Buddhism got new development in Tibetan area with different sects emerging such as Nyingma, Kagyu, Sakya, Khadampa, etc., marking the formation of Tibetan Buddhism. At that time, the succession of the leaders of various sects was largely based on master-apprentice relationship or family relationship. In the middle of the 13th century, when Mongols unified China, Tibetan Kagyu, Sakya and other sects established contact with Mongol rulers. Sakya Pandita Kunga Gyaltsen (1182-1251) was summoned to Liangzhou (present-day Wuwei of Gansu province) and talked about subordination issues with Godan (1209-1259), son of Emperor Taizong of the Yuan Dynasty. Therefore, Sakya Pandita Kunga Gyaltsen wrote a letter to all Tibetan political and religious leaders about the meeting (Fig. 1). In 1260, Emperor Shizu of the Yuan Dynasty, Kublai was enthroned. The Yuan Dynasty granted the leader of Sakya, Phagba (1235-1280), the titles of State Master, Master of Emperor, Great Treasure Dharma-Raja successively. The Yuan Dynasty set up the Zongzhi (meaning General Regulation) Yuan (renamed as Xuanzheng Yuan later) to administrate the Buddhist affairs over the nation and within Tibetan region (refer to Illustration 82). The Sakya sect was appointed to take administrative and religious powers of Tibet.