The first three Chakkri kings, by succeeding each other without bloodshed, had brought the kingdom a degree of political stability that had been lacking in the Ayutthaya period. There was, however, no rule providing for automatic succession to the throne. If there was no uparaja at the time of the king's death -- and this was frequently the case -- the choice of a new monarch drawn from the royal family was left to the Senabodi, the council of senior officials, princes, and Buddhist prelates that assembled at the death of a king. It was such a council that chose Nang Klao's successor. During this period (King Rama II, Rama III and Rama IV) tried to create the first semblance of a modern government,creating ministries and appointing chief ministers to help with the running of the government. Rama IV was significantly interested in the western knowledge. When King Chulalongkorn (or Rama V) ascended the throne as King of Siam in 1868, due to pressure of old generation dignitaries and high officials, he decided to embrace many European and Western ideas. Under the tougher pressure from western imperialists, old tributaries kingdoms of Siam such as Laos and Cambodia came under French control.
Rama V began close contact with the western powers so that Siam could avoid being colonized. King Chulalongkorn himself was educated by Westerners, and was intent on reforming the monarchy along Western lines. First he abolished the practice of kneeling and crawling in front of the monarch and repealed many laws concerning the relationship between the monarch and his people. Instead he created a monarchy based on western lines of an ‘enlightened ruler’; absolute but enlightened. However he continued to preserve many ancient aspects and rituals of the old kingship, including his religious and feudal powers. His son King Vajiravudh (or Rama VI) (succeeded in 1910) continued his father’s zeal for reform and brought the monarchy into the 20thcentury. He was succeeded by his brother King Prajadhipok (or Rama VII) in 1925.
In June 1932, a group of foreign educated students and military men called “the Promoters” carried out a bloodless coup, or so-called Revolution, seizing power and demanded that King Prajadhipok grant the people of Siam a constitution. The King agreed and in December 1932 the people were granted a charter, ending almost exactly 150 years of absolute Chakri rule. From then on the role of the monarch was supposedly relegated to that of a symbolic head of state. Yet his majesty is traditionally revered and inviolable according to the Constitutions. The king no longer had power in issuing laws and orders. In 1935 King Pradhipok abdicated the throne, following disagreements with the increasingly controversial government. Rama VII lived in asylum in the United Kingdom until his death.