Chea Sim: Politician who left the Khmer Rouge and became a key figure in Cambodia after the fall of the brutal regime

Sim's image is seen on billboards around Cambodia promoting the ruling party

Chea Sim in 2010; he was both ally and rival of Hun Sen, and in recent years his power had been negligible (AP)

Chea Sim was a key figure in Cambodia after the fall of the brutal Khmer Rouge regime and an ally of the current leader, Prime Minister Hun Sen. He had been President of the ruling Cambodian People's Party since its formation in 1991, and President of the Senate since 1999.

Born into an ethnic Chinese peasant family in 1932, he joined the revolutionary movement against colonial France in the early 1950s and like Hun Sen was a member of the communist Khmer Rouge when it seized power in 1975 after a civil war. Both men fled the group to join a resistance faction groomed by neighbouring Vietnam, which installed them as Cambodia's new leaders after defeating the Khmer Rouge in 1979.

Chea Sim's image is seen on billboards around the country promoting the ruling party, but his actual power over the past decade was negligible as Hun Sen consolidated his own power base. In April, when Chea Sim's health was deteriorating, Hun Sen – two decades younger – said he would take over as party leader when Chea Sim died.

The two men were allies but also rivals, and in the 1990s Chea Sim led a faction that tentatively challenged Hun Sen. But Hun Sen, one of South-east Asia's most wily and ruthless politicians, kept him at bay.

An open break came in 2004, when they disagreed over changing the constitution to allow an opposition party to join in a coalition government. When Chea Sim, as acting head of state, refused to sign off the change, Hun Sen pushed it through by forcing him into temporary exile, a show of power which marked the decline of Chea Sim's influence.

MARTHA MORRIS

Chea Sim, politician: born French Indochina 15 November 1932; married Nhem Soeun; died Phnom Penh, Cambodia 8 June 2015.