Hun Sen has been a leading figure in Cambodian politics for more than two decades [AFP]
Hun Sen has been the prime minister of Cambodia for 23 years. He is one of the main leaders of the Cambodian People's Party (CPP), which has governed the country since the Vietnamese-backed overthrow of the Khmer Rouge in 1979.
Since the restoration of multi-party democracy in 1993, the CPP has been in a coalition with the royalist Funcinpec party. It has been the senior partner since 1997.
Hun Sen has a glass eye, the result of a wound sustained during the Khmer Rouge offensive against Phnom Penh in April 1975.
When the Khmer Rouge government was overthrown, he was appointed foreign minister of the Vietnamese-installed People's Republic of Kampuchea in 1979.
He became prime minister of the country in 1985. From 1993 until 1998 he was co-prime-minister with Prince Norodom Ranariddh.
In 1997, the coalition was shaken by tensions between Hun Sen and Prince Norodom Ranariddh, the Funcinpec leader.
Funcinpec began to collaborate with the remaining Khmer Rouge rebels, aiming to absorb them into its ranks.
Grab for power
In response, Hun Sen launched a bloody military coup, removing Norodom Ranariddh and becoming the country's sole prime minister in 1998.
Several royalist supporters were killed or tortured by CPP members, though Hun Sen denied any involvement.
He also denied that his action was a coup, arguing that if he had wanted to make a coup, he would have abolished the monarchy.
The elections of July 2003 resulted in a larger majority in the national assembly for the CPP, with Funcinpec losing seats to the CPP and the Sam Rainsy Party, headed by and named after Sam Rainsy, Hun Sen's main rival.
However, CPP's majority was short of the constitutionally-required two-thirds for the CPP to form a government alone.
This deadlock was overcome through a new CPP-Funcinpec coalition, formed in mid-2004.
This year's election has not been defined by violence, but by alleged voter intimidation, in which critics claim will not lead to a free and fair election.
However, Hun Sen is expected to win the poll.
His main campaign hook continues the reflect the CPP as Cambodia's lilberator from the Khmer Rouge.