Lợi's former comrades now fought politically with each other to control the court. Lê Sát used his power as the young emperor's regent to purge opposition factions. When Lê Thái Tông found out about Le Sat's abuses of power, he allied with Lê Sát's rival, Trịnh Khả. In 1437, Lê Sát was arrested and given a death sentence. In 1439 Lê Thái Tông launched a campaign against rebelling Tai vassals in the west and Chinese settlers in Đại Việt. He ordered the Chinese to cut their hair short and wear clothes of the Kinh people. One of his sisters raised in China was forced to commit suicide, being accused of endless conspiracies. Later he had four princes: The eldest son Lê Nghi Dân, the second Lê Khắc Xương, the third Lê Bang Cơ, and the youngest Lê Hạo. In 1442 the emperor died in suspicion after a visit to Nguyễn Trãi's family. Nguyễn Trãi and his clan, relatives were innocently condemned to death. One-year-old Lê Bang Cơ (Lê Nhân Tông, r. 1442–1459) assumed the throne a few days after his father's death. The emperor was too young and most political power of the court fell Lê Lợi's former comrades Trịnh Khả and Lê Thụ, who allied with the queen mother Nguyễn Thị Anh. During the dry season of 1445–1446, Trịnh Khả, Lê Thụ, and Trịnh Khắc Phục attacked Champa and took Vijaya, where the king of Champa Maha Vijaya (r. 1441–1446) was captured. Trịnh Khả installed Maha Kali (r. 1446–1449) as a puppet king, however, three years later Kali's elder brother murdered him and became king. Relations between the two kingdoms downfall into hostility. In 1451, amidst chaotic political struggles, Queen Nguyễn Thị Anh ordered Trịnh Khả to be executed for an accusation of conspiracy against the royal throne. Only two of Lê Lợi's former comrades, Nguyễn Xí and Đinh Liệt were still alive. During a night in late 1459, Prince Lê Nghi Dân and followers stormed into the palace, stabbed his half-brother and the mother. Four days later he was proclaimed as emperor. Nghi Dân ruled the kingdom for 8 months, then the two former-Nguyễn Xí and Đinh Liệt carried a coup against him. Two days after Nghi Dân's death, the youngest prince Lê Hạo was crowned, known as Emperor Lê Thánh Tông the Overflowing Virtue (r. 1460–1479). Lê Thánh Tông's reforms In the 1460s, Lê Thánh Tông carried