Prime Minister of Thailand sixteen out of twenty-nine, including the incumbent General Prayut Chan-o-cha. Military dominance began with the country's second Prime Minister, Phot Phahonyothin, who ousted his civilian predecessor in a coup in 1933. The longest serving Prime Minister was Field Marshal Plaek Pibulsonggram at 14 years, 11 months and 18 days. The shortest was Tawee Boonyaket at just 18 days. Nine were removed by coups d'état, three were disqualified by court order, and eleven resigned from office. The youngest ever to occupy office was M.R. Seni Pramoj at 40 years old. Thailand received its first female prime minister, Yingluck Shinawatra, in 2011.
Prime Minister of Canada on the prime minister's power: the commons may revoke its confidence in an incumbent prime minister and Cabinet or caucus revolts can quickly bring down a serving premier and even mere threats of such action can persuade or compel a prime minister to resign his post, as happened with Jean Chrétien. The Reform Act, 2014, codifies the process by which a caucus may trigger a party leadership review and, if necessary, chose an interim leader, thereby making a prime minister more accountable to the MPs in his or her party. Caucuses may choose to follow these rules, though the decision