Si Votha was a grandson of King Ang Eng (1772–1796) and a son of King Ang Duong. His biographical notes only record that he had a daughter named Neak Ang Mechas (Princess) Ang Duong Rath Votha. Si Votha had two half-brothers, Norodom and Sisowath of Cambodia, with Norodom being the king's chosen heir. Upon King Ang Duong's death, a succession struggle ensued, with Si Votha attempting to take power while his half brother Norodom was occupied with a rebellion; eventually Norodom gained the upper hand when he gained the backing of Sisowath.