Former Premier Stages Coup D'Eta In Siam - Special Guard For Young King. Field-Marshal Phibun Songkram, Premier of Siam during the Japanese occupation and the Minister who declared war on the Allies in 1942, seized power in Bangkok overthrowing the Siamese Government and taking ***** of all military and civil installations. Songkram, in a statement broadcast to the Siames people, declared that experienced administrators would be recalled to power in an effort to place the country on a sound footing. November 19, 1947.