BANGKOK — Prem Tinsulanonda, an army commander in chief who served as prime minister of Thailand and later became the head of the influential Privy Council of the king, died on Sunday in Bangkok. He was 98.

His death was confirmed by Chai Chidchob, a senior lawmaker in the National Assembly, which observed a minute of silence in Mr. Prem’s honor.

Without facing a general election, Mr. Prem held the prime minister’s post with the backing of the king from 1980 to 1988, shuffling cabinets five times and weathering two coup attempts.

He left much of the day-to-day administration to bureaucrats, weakening the influence of political parties and the military.