After the failure of Siam (Thailand) to regain hegemony over Cambodia, a Vietnamese-installed queen reigned on the Cambodian throne as her country increasingly came under the yoke of Vietnam. Vietnamese oppression caused a general uprising in 1841, with Cambodians slaughtering their Vietnamese overlords and others, soliciting help from Siam, and requesting Cambodian prince Ang Duong (1796-1860) to return from exile in Bangkok and become king. Siamese king Rama III (d. 1851) sent an army that installed Ang Duong on the Cambodian throne (1841). Vietnam, which had more than 50 garrisons throughout Cambodia, waged a savage four-year war against rural insurgents and Siamese troops, sustaining defeat in general but refusing to withdraw from the country. Finally, in 1845, both sides agreed to a compromise peace, which place Cambodia under joint Siamese and Vietnamese protection but with a Siamese predominance. In 1848, Ang Duong was formally crowned Cambodia's king.