May 26 (UPI) -- Thailand's former prime minister and top adviser to the country's late king died Sunday at the age of 98 on Sunday, his aides said.
Gen. Prem Tinsulanonda died of heart failure at Phra Mongkut Hospital in Bangkok, Thai newspaper Khaosod reported.
Tinsulanonda was born in southern Thailand in 1920 and first became involved with Thailand's military and politics when he began serving as a member of the constitution drafting committee in 1959.
He eventually rose to the rank of general, and moved up the political ladder serving as a senator, member of parliament, deputy prime minister and finally prime minister in 1980.
Tinsulanonda served as prime minister for eight years, where he presided over multiple coup attempts and growing tension with parliament, before stepping town to serve as His Majesty the King's Privy Councilor in 1988.
He was revered by some as one of King Ram IX's most trusted advisers who worked to unite Thailand, while detractors viewed him as someone who sought to oppose elected governments.
More than 300 people gathered to hold a vigil at Phathammarong Museum, on the site of Tinsulanonda's birthplace, according to the Bangkok Post.
The crowd was made up of government officials, alumni of Tinsulanonda's primary school and other's who considered the leader a "father" of the people from the Thai city of Songkhla.
"We people of Songkhla are very proud of what Gen Prem had done for us and all Thai people throughout his life," one mourner said.