In 1769, King Taksin of Thonburi sent a letter to the pro-Vietnamese King Ang Ton of Cambodia, urging Cambodia to resume sending the submissive tribute of golden and silver trees to Siam. Ang Ton refused on the grounds that Taksin was a Chinese usurper. Taksin was angered and ordered the invasion to subjugate Cambodia and install the pro-Siamese Ang Non on the Cambodian throne. King Taksin invaded and occupied portions of Cambodia. The following year a proxy war between Vietnam and Siam erupted in Cambodia when the Nguyễn Lords responded by attacking Siamese cities. At the outset of the war, Taksin advanced through Cambodia and placed Ang Non II on the Cambodian throne. The Vietnamese responded by recapturing the Cambodian capital and installing Outey II as their preferred monarch. In 1773, the Vietnamese made peace with the Siamese in order to deal with the Tây Sơn rebellion, which was a result of the war with Siam. Two years later Ang Non II was proclaimed the ruler of Cambodia.