In 1833, as Minh Mạng had been trying to take firm control over six southern provinces, a large rebellion led by Lê Văn Khôi (an adopted son of the Saigon viceroy Le Van Duyet) against Minh Mạng in Saigon, attempted to establish the brother of Minh Mạng, Prince Cảnh's line to the throne. The rebellion lasted for two years, gathered support from Vietnamese Catholics, Khmers, Chinese merchants in Saigon, and even the Siamese ruler Rama III until it was crushed by the government forces in 1835. In January, he issued the first kingdom-wide prohibition of Catholicism, and began persecuting Christians. 130 Christian missionaries, priests and church leaders were executed, dozens of churches were burned and destroyed during his persecution.