The Siamese king Rama I died in 1809. King Ang Chan II refused to attend his royal cremation. Instead, Ang Chan sent three Cambodian princes, including Ang Snguon, Ang Em and Ang Duong, to attend the funeral. Ang Em was appointed Cambodian Upraracha by Rama II. The Uprayorach Ang Snguon ousted Ang Chan in 1811. After Vietnamese intervention, Ang Snguon, Ang Em and Ang Duong fled to Bangkok.
