Prime Minister of Thailand Rajanubhab took over this role. In fact, the office most considered the precursor of that of the prime minister was the ancient office of "Samuha Nayok" (สมุหนายก), which was run by an "Akkhra Maha Senabodi" (อัครมหาเสนาบดี) or "chief minister in charge of civilian affairs". The first Prime Minister of Siam was Phraya Manopakorn Nititada, a judge. The title of the office was changed from "Prime Minister "of Siam"" to "Prime Minister "of Thailand"" in 1945 and then permanently with the renaming of Siam to Thailand in 1949. For most of its existence the office has been occupied by Army leaders;
Prime Minister of Japan the head of the "Daijō-kan" (Department of State), the highest organ of Japan's pre-modern Imperial government during the Heian period and until briefly under the Meiji Constitution with the appointment of Sanjō Sanetomi in 1871. The office was replaced in 1885 with the appointment of Itō Hirobumi to the new position of Prime Minister, four years before the enactment of the Meiji Constitution, which mentions neither the Cabinet nor the position of Prime Minister explicitly. It took its current form with the adoption of the Constitution of Japan in 1947. To date, 62 people have served this position. The current