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;
Niwatthamrong Boonsongpaisan from Chulalongkorn University and is married to Boonphatcharee Boonsongpaisan. A close business associate of Thaksin Shinawatra, Niwatthamrong served as the Chairman of the Executive Committee-Media and Advertising front of Shin Corporation since 1995 and as Vice-Chairman since 2000. He served from 2001 to 2002 as Vice-Chairman of iTV and from 1993 to 1995, director of that company between 2002 and 2008, and a member of the board of directors between 2008 and 16 March 2010. Niwatthamrong served as director of the controversial rice pledging scheme, where rice was bought at inflated prices from farmers and subsequently was left to rot