This 1955 photo shows former leader of the banned Communist Party of Malaya Chin Peng, left, during negotiations between the communists and the British-ruled government. (NATIONAL ARCHIVES OF MALAYSIA/AFP/Getty Images)

Chin Peng, a wily and fanatical communist guerrilla who was decorated by the British for helping expel Japanese invaders from Southeast Asia during World War II and then led a brutal 12-year insurgency against the English colonial rulers in his native Malaya, died Sept. 16 in a Bangkok hospital.

He was reported to be 88, but his age could not immediately be confirmed. The cause was cancer, his former lawyer, Darshan Singh Khaira, told the Associated Press.

The Malayan “emergency,” as it was called by the British, lasted from 1948 to 1960. The violence killed more than 10,000 people, including many civilians. Chin Peng, a onetime secretary-general of the Communist Party of Malaya, kept up his ruthless fight even after the former colonial protectorate of Malaya gained independence in 1957 and after the new country became part of Malaysia in 1963.

Rufus Phillips, a scholar of guerrilla warfare and author of “Why Vietnam Matters,” said in an interview that Chin Peng was the figure who “really spearheaded the whole emergency.”

Chin Peng’s guerrilla fighters burned villages, attacked police stations and orchestrated assassinations before an overwhelming military force supplied by the British Commonwealth nations pushed his movement deep into the jungle. His indiscriminate attacks robbed him of much of his popular support, and British promises of Malayan independence sapped the rest.

At its height, the Malaya crisis was an international battleground in the fervid conflict between nationalism and anti-colonialism. In time, the fight there was overshadowed by the burgeoning war in Vietnam. Once a formidable outlaw, Chin Peng gradually faded into “irrelevance,” Phillips said, especially as Malaysia’s economic might grew in the 1970s.

Prime Minister Najib Razak told the Malaysian newspaper the Star that Chin Peng “will be remembered in Malaysia as a terrorist leader of a group that waged war against the nation and caused immeasurable cruelty to the people and attacking our security forces.”

Chin Peng — a name he took as his nom de guerre — did not officially surrender until 1989, making him one of the world’s longest-surviving communist guerrilla leaders. “I fought a liberation war,” he wrote in his 2003 memoir, “My Side of History.” “To ask whether I would do it again is idle talk. . . . You can tell me I was wrong. You can tell me I failed. But I can also tell you how it was and how I tried.”

The son of a bicycle dealer who had emigrated from China, he was born Ong Boon Hua in the northern Malay state of Perak. The reported years of his birth range from 1920 to 1924.

He joined the Communist Party of Malaya in his teens, inspired after reading Mao Zedong’s manifesto “On Protracted War.” He was described as studious, learning four Chinese dialects as well as Malayan and English, and was deeply offended by what he perceived as the economic exploitation of the country’s Chinese and Indian ethnic minorities.

The Malay peninsula was one of the British Empire’s most important economic engines, providing a steady supply of tin and rubber until the Japanese drove out most of the Anglo colonists in 1942, during World War II.

An elite group of British military and intelligence forces stayed behind, partnering with the Malayan People’s Anti-Japanese Army (MPAJA). Chin Peng became one of the communist-backed organization’s most seasoned and fiercest members and an essential liaison between the MPAJA and Britain’s special operations unit known as Force 136.

“I used the trunk roads and then the estate roads to avoid being spotted,” he told a Singaporean newspaper in 2009, describing how he’d meet the British operatives arriving by submarine. “I cycled everywhere.”

F. Spencer Chapman, a British army officer highly decorated for his military record in Malaya, once called Chin Peng “Britain’s most trusted guerrilla representative.”

In 1945, he participated in a victory parade in London and was honored with an appointment to Officer of the Order of the British Empire. The distinction was later withdrawn when he began a merciless terror campaign to evict the colonial powers who had bestowed it on him.

“The British were desperate and found us useful,” Chin Peng wrote in his memoir. “Conveniently, we both wanted to defeat the Japanese. The fact of a common enemy, however, brought no change to Britain’s long-term aim — a return to the colonial status quo ante. Neither did this common enemy change our agenda which looked to independence from colonial domination and the founding of a Democratic Republic of Malaya.”

The Communist Party of Malaya, which passed a resolution in 1948 advocating “the capture of power by the peasants and workers by any means,” drew thousands of followers with Chin Peng as its leader. Many were ethnic Chinese who had been denied legal and political protections long granted to the dominant ethnic Malays.

The communists led crippling labor strikes and then turned to violent methods. They used mostly British weapons left over from arms caches dropped by airplane and hidden in the jungle during World War II.

On the morning of June 16, 1948, communist guerrillas slaughtered three British rubber planters, leading to months of chaos. Forces loyal to Chin Peng ambushed and assassinated the British high commissioner for Malaya, Henry Gurney, in 1951.

The British began making preparations for a full-scale combat operation to wipe out the insurgency. The colonial government declared not a war but rather a “state of emergency,” a word choice that allowed plantation owners to be compensated for any losses in insurgent attacks.

The Korean War, meanwhile, led to a surge in prices for Malaya’s rubber, rice and tin, and the British government used the windfall to fund its counterinsurgency efforts. About 70,000 Commonwealth troops fought against an estimated 10,000 guerrillas.

Chin Peng’s increasingly desperate followers retreated far into the jungle, where they threatened and killed villagers as they sought food, money and supplies.

At the same time, the British engaged in a massive effort to isolate and protect more than 400,000 ethnic Chinese — Chin Peng’s presumed base of support for sustenance and intelligence. Most were uprooted from their farms and rural outposts and resettled in well-guarded compounds known as “new villages,” which supplied vastly improved access to sanitation, health care and education.

The British offered a $42,000 bounty for Chin Peng’s corpse and almost double the amount to anyone who could capture him alive. The guerrilla leader refused offers of amnesty by the British and later leaders of independent Malaya.

“The amnesty means surrender,” hedeclared in 1955. “Surrender means humiliation. We will not accept surrender at any time. We will carry on the struggle to the last man.”

Chin Peng’s ragtag group — holed up near the Thai border — continued to strike at what it considered a lapdog post-colonial government. Malaya declared an end to the “emergency” in 1960.

Chin Peng moved to China and reportedly continued to extort money from businesses to sustain his dwindling band of followers. He gradually lost the support of his former Chinese patrons and reached a peace accord with Malaysian authorities in 1989, after which he lived in obscurity in Thailand.

Chin Peng was reportedly married and had at least two children, but information about survivors could not be independently confirmed.

About a decade ago, Chin Peng filed a lawsuit to return to his homeland, where he remained persona non grata. The country’s top court ruled in 2009 that he needed birth and citizen certificates to reenter. Both had been seized by the British in the late 1940s.