From 1932 to 1990 Thailand has been ruled primarily by military regimes, with intermittent periods of democratic rule. The strong military and bureaucratic elites controlled Thai politics and prevented the development of democratic institutions.
The reason are kicked off a period of seesaw politics, marked by frequent attempts by pro-Thaksin "red-shirts" and anti-Thaksin "yellow-shirts" to use mass protests as a lever to eject the other side from power.
The military under the leadership of General Prayuth Chan- ocha, Commander of the Royal Thai Army (RTA), launched a coup d’état against the caretaker government of Thailand on 22 May 2014. Initially declaring martial law on May 20, calling the move “softer than a coup,” Army Commander Prayuth Chan-ocha formalized the military coup two days later. The military then dissolved the Parliament, detained political leaders and academics, imposed a curfew, and restricted media outlets. The military established a junta called National Council for Peace and Order (NCPO) to govern the nation. On 21 August he was named prime minister by the legislature, in a move that was widely expected. Under Gen Prayuth, the military had hand-picked the legislature, populating it with mostly military and police figures. It also issued an interim constitution in July that gives the military sweeping powers. On September 30th, the coup leader and prime minister, Prayuth Chan-ocha, stepped down from his position as army chief. His successor, General Udomdej Sitabutr, has assured Mr Chan-ocha that the army will not oust his brand-new government with a military counter-coup. It almost went without saying that General Sitabutr will do everything in his power to protect the monarchy.