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;
2014 Thai coup d'état Niwatthamrong attempted to establish a government-in-exile at the United States embassy in Bangkok, but the embassy denied the report. On the night of 22 May 2014, military officers detained additional politicians, including Chalerm Yubamrung and his sons. The following day, the NCPO summoned PTP members and Shinawatra family members, including Yingluck. Niwatthamrong and Yingluck surrendered themselves to the NCPO on that day. Yingluck was detained at an undisclosed "safe house". The NCPO said it released her on 25 May. The NCPO later summoned another 114 prominent figures from both sides and stated that those who refused to submit to it