The Prime Minister of Thailand is the head of government of the Kingdom of Thailand. The prime minister is also the chairman of the cabinet of Thailand and represents the government at home and the country abroad.
The post of prime minister has existed since 1932, after a bloodless revolution forced the absolutist King Prajadhipok to grant for the people of Siam their first constitution. Under the newly established constitutional monarchy, the first prime minister of Siam was Phraya Manopakorn Nititada. At first, the office was called the President of the People's Committee, it was later changed to Prime Minister of Siam when the king deemed it too communistic.
Constitutionally the prime minister is required to be a member of the lower house of parliament or the House of Representatives. He must also gain their approval through a resolution before an official appointment by the king can take place. As a result the prime minister might succumb to a vote of no confidence and removal in the House, however this has never happened up to date.