Boun Oum (also Prince Boun Oum or Prince Boun Oum Nachampassack) (December 12, 1912-March 17, 1980) son of King Ratsadanay, was the heir to the defunct throne of Champassack. A political conservative sympathetic to French control of Laos, he commanded a force of 15,000 that fought Japanese occupiers and the Lao Issara in the south of Laos. Titular leader of the royalist faction, he served as prime minister of the Kingdom of Laos in 1948 - 1949 and again in 1960 - 1961. He retired from politics to pursue business interests from his base in Pakxe and Champassack but continued to be a major power broker until his exile in 1975, the year the communists came to power.