 Government authority under five-year-old Ratsadathirat proved to be weak.In 1534, only five months after his nephew's ascension, Chairacha marched to Ayutthaya to stage a coup, killed his nephew, and took the throne of Ayutthaya.In 1539, King Tabinshwehti attacked the Mon people inhabiting Chiang Kran, but under Siamese rule.