TIMELINE: Cambodia marks thirty years since Khmer Rouge

(Reuters) - Thousands of Cambodian survivors of the Khmer Rouge "Killing Fields" marked 30 years on Wednesday since the fall of Pol Pot's ultra-Maoist regime, blamed for the deaths of 1.7 million people. A handful of aging and infirm leaders from the movement are being tried at a joint Cambodian-United Nations tribunal three decades after their disastrous attempt to create an agrarian utopia ended.

Here is an overview of the rise and fall of the Khmer Rouge.

1953 - King Norodom Sihanouk proclaims independence from France, but soon abdicates to go into politics.

March 1969 - Secret U.S. bombing of Vietnamese communist bases in Cambodia begins.

March 18, 1970 - U.S.-backed premier Lon Nol ousts Sihanouk as prime minister while the latter is on an overseas trip.

April 17, 1975 - Khmer Rouge seize Phnom Penh and immediately start emptying cities and towns in a bid to create a totally agrarian society. An estimated 1.7 million people die during their nearly four years in power.

Dec 25, 1978 - Vietnam starts invasion of Cambodia after a series of increasingly daring cross-border Khmer Rouge raids.

Jan 7, 1979 - Vietnamese troops occupy Phnom Penh, driving Pol Pot to the Thai border. The occupation is to last 10 years.

May 1993 - U.N.-run election produces shaky coalition between Sihanouk's son, Prince Norodom Ranariddh, and Hun Sen, a former Khmer Rouge guerrilla installed as PM by Hanoi in the mid-1980s.

July 1997 - Pol Pot ousted as Khmer Rouge leader.

April 15, 1998 - Pol Pot dies in the jungle-clad mountain redoubt of Anlong Ven on Thai border.

Feb 9, 1999 - Last Khmer Rouge guerrillas surrender.

March 2003 - After years of negotiations, Cambodia and the U.N. sign deal to set up a joint "Killing Fields" court. Almost six years later, the court has detained five top cadres but no full trial has started.

Source: Reuters