Prime Minister's Office (Sri Lanka) the Parliament. The office of prime minister was formed in 1947 with D. S. Senanayake becoming the first Prime Minister of Ceylon. It consisted of a Secretary (Permanent Secretary) and an Assistant Secretary, who were officers of the Ceylon Civil Service, and a Private Secretary, along with clerical and support staff based at the Senate Building along with the Senate, Cabinet office and the Ministry of External Affairs and Defence. Since 1960 the prime minister's office has been based at Sirimathipaya Mansion on Sir Ernest de Silva Mawatha (formerly Flower Road), Colombo which was the former residence of philanthropist Sir
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.