Ruling Cambodian People’s Party president Chea Sim, considered the second-most-powerful figure in government for much of the period since the fall of the Khmer Rouge regime, died yesterday at his home aged 82.

The octogenarian, who was also the president of the Senate, had long dealt with ill health and made repeated trips oversees for medical attention since suffering a stroke in October 2000.

In a statement yesterday, the Senate announced that Sim, who suffered from diabetes, died at 3:45pm, adding that the National Assembly would shut down today for a period of mourning.

CPP spokesman Suos Yara said Prime Minister Hun Sen was by Sim’s side within 30 minutes of his death.

“The whole nation and the party pay tribute to the loss of our statesman, who liberated Cambodia from the genocidal regime,” Yara said, praising Sim as a “humble” and “kind” man of the people.

“He is the leader of our party and the chair of the Senate, so we will be organising a state ceremony.… The solidarity and love among our statesmen and our members is very strong,” he added, referring to Hun Sen’s visit to the family.

Late yesterday evening, a directive signed by the prime minister declared Friday, June 19, an official day of mourning, with government offices to be closed and flags flown at one-third mast.

Cambodia National Rescue Party spokesman Yim Sovann said the opposition had also expressed their condolences to Sim’s family.

“He has worked very hard for Cambodia,” Sovann said.

Prime Minister Hun Sen and Chea Sim share a laugh at the Cambodian People’s Party headquarters in 1999. AFP

Staring down from billboards around the country, an anointed member of the ruling CPP’s triumvirate of “Samdechs” along with Prime Minister Hun Sen and National Assembly President Heng Samrin, Sim long served as a key foundation of the government’s political power.

President of the Cambodian People’s Party since 1991, he was also the leader of the largest CPP faction outside of Hun Sen’s own core power base of supporters, and in the 1980s was often referred to as Cambodia’s “strongman”.

Born on November 15, 1932, in Romeas Hek district of Svay Rieng province, Sim graduated from a Buddhist school and in 1951 joined the Issarak movement, which was fighting for independence from French rule, according to his biography.

In 1970 he joined the Khmer Rouge and, following the ultra-Maoist movement’s 1975 toppling of the Lon Nol regime, rose to become secretary of Ponhea Krek district in the Eastern Zone region, in what is now Tbong Khmum province.

Amid Pol Pot’s internal purges, Sim fled to Vietnam and along with Hun Sen, Heng Samrin and Pen Sovann, became one of the leaders of the Vietnamese-backed Kampuchean United Front for National Salvation, which joined Vietnamese troops in overthrowing the Khmer Rouge in 1979. He was appointed the party’s vice president at the age of 46.

At the time, historian Evan Gottesman wrote, Sim, with his stocky build and cropped hair, looked to be one of the few Cambodians not starving under the Khmer Rouge.

In the People’s Republic of Kampuchea (PRK) regime installed afterward by the Vietnamese, Sim quickly rose to prominence, appointed as minister of interior and chair of the party’s internal security committee.

He quickly promoted friends and family into the fledging bureaucracy, helped the Vietnamese co-opt former Khmer Rouge cadres into the new government and, behind the scenes, built a personal patronage network in the provinces and the security apparatus which would form the backbone of his political capital in the years to come.

In 1981, according Gottesman, Sim’s influence became concerning to the Vietnamese, and he was moved out of the Ministry of Interior to the largely ceremonial role of president of the National Assembly.

But Sim remained at the heart of the then-PRK’s internal security apparatus and continued to command strong allegiances with high-level members of the party, including the man seen as his factional successor – the current interior minister and Sim’s brother-in-law, Sar Kheng.

In a September 1990 profile titled “Cambodia’s populist hero”, the Los Angeles Times wrote: “Despite his relatively low profile outside the country, Cambodian officials and many diplomats in Phnom Penh describe Chea Sim as the real power center in Cambodia.”

Throughout the present regime’s more than 30 years of rule, Sim and Hun Sen, who was appointed prime minister in 1985, maintained a dependent but fractious relationship.

Following a failed coup attempt in 1994 by disgruntled CPP officials, the prime minister began a series of moves to shore up his own network and undercut his rival.

Hun Sen installed Hok Lundy, an ally, as the next National Police chief, and began turning his personal bodyguard unit into a de facto army. In 1997, despite opposition from Sim and other prominent CPP members, he launched the July coup against Prince Ranariddh’s Funcinpec.

However, many see the real turning point in the battle between the two CPP titans as coming in 2004, when Sim was escorted out of the country by Lundy’s police.

Ostensibly taken to Bangkok for “medical reasons”, Sim had refused to sign off, as acting head of state, on constitutional changes that would allow CPP and Funcinpec to form a coalition government, reportedly unhappy that his allies were being cut out of government.

Though his base was to be further eroded – including the 2011 arrest of a number of Chea Sim-linked officials, among which was his chief bodyguard – Sebastian Strangio, author of Hun Sen’s Cambodia and a former Post reporter, said Sim was always able to put conflicts with Hun Sen aside when came it to protecting the CPP.

King Norodom Sihanouk waves at the inauguration ceremony of the new Senate body at the Royal Palace in Phnom Penh in 1999, watched by the new Senate president Chea Sim (left). AFP

“Without this united front against the party’s external enemies, the CPP would never have been able to remain in power for so many years,” Strangio said.

Strangio said Sim’s death was unlikely to significantly alter the wider balance of power within the party, as his role in government had become “mostly symbolic” as he had succumbed to illness.

“The CPP’s internal workings are so opaque that it is hard to say what the impact of his death will be,” Strangio said, adding that Sim’s faction would be further eroded by the death of the “pillar of the old guard”.

In April, Hun Sen announced his intention to take Sim’s position as head of the party when he died.

However, Suos Yara yesterday said the prime minister will continue in his role as “acting president” until the CPP votes on a new leader.

Likewise, Sim’s position as Senate president will be held in caretaker fashion by Senate First Deputy President Say Chhum until the upper house elects a replacement, Yara said.

Whether or not Sim’s position as head of the ruling party went to the prime minster, Strangio said it would only have a minimal impact on the balance of power in the CPP.

“In Cambodian politics, formal titles are less important than the ability to mobilise support along patronage lines,” he said.

“Becoming party chief would augment Hun Sen’s stature, but in practical terms would merely formalise a status quo that has existed for years.”

Political commentator Ok Serei Sopheak said that although the succession plans had likely been long-cemented, it would be important to watch impending reshuffles of the party in the coming months.

“The prime minister gets the number one position, but who will be officially announced number two and number three and so on, and so on,” Sopheak said.

“When that’s announced, then you can analyse the dynamic of the news today.”

Sopheak, who met Sim on a number of occasions while working in the Interior Ministry in the ’90s, said he remembered Sim as having a “sharp analytical appreciation of the country”.

“He was a great nationalist but without extremism, and he always talked about the situation with the agriculture of the villagers, of the grassroots community. I guess it is where he came from, where he belongs,” Sopheak recalled.

Sim’s wife, Nhem Soeun, died in 2009. Sim is survived by his six children.

ADDITIONAL REPORTING BY CHEANG SOKHA AND VONG SOKHENG