King Rama I - King Rama III (1782-1851)

During the early Rattanakosin period, promotion of good health and the well-being of the people took the form of announcements and speeches by the King. For example, when the Prachetupon Vimolmanklaram Temple was restored, King Rama I ordered the compilation of medical textbooks and sculptures of hermits in different postures to educate the people on health care. King Rama II reviewed the medical textbooks to make the use of medicines and medical treatments more accurate and safe. During a further restoration of Wat Phrachetupon in 1832, King Rama III had ancient medical, pharmaceutical and massage textbooks inscribed and replaced the hermit sculptures with cast metal sculptures that can still be seen today. King Rama III also had poets compose poetry that rhymed with the hermits' names and had rare herbs planted in the temple. His intention was to conserve ancient medical knowledge and other kinds of ancient knowledge. Wat Phrachetupon was then called the first college of Thailand. Apart from this, King Rama III contributed to modern medical treatment development as well, encouraging royal doctors to learn from American missionaries about smallpox vaccination.

King Rama IV

King Rama IV was the first king to introduce Western modernisation to the country. His son, King Rama V adhered to his ideals and expanded many aspects of them, founding the basis of the modern economy. King Rama IV signed a Treaty of Friendship and Commerce between Siam and Great Britain (Bowring's Treaty 1855.). After signing the Treaty, the Thai economy began to change from a self-sustaining to a monetary economy and international trade expanded. Money was used as a means of exchange. There was improvement in the design and production of money. In 1860, Machinery was imported to make coins in place of Pod-Duang. The basis of revenue collection was laid and land taxation was improved. Also, the King laid the basis for social reforms such as reducing the compulsory labor service and improving the status of women. In terms of communication, he laid the basis for modern communications, constructing western-style streets and canals to facilitate water transportation as well as initiating a postal service. In terms of the military, the King developed the military by, for instance, hiring British captains as army trainers.

King Rama V

Major changes were initiated during his reign in terms of administration, education, etc. A very significant aspect of social reform was the abolition of slavery. This was one of his great achievements. It proceeded gradually and it took almost 30 years to overcome obstacles and resistance from slave's owners and the slaves themselves. The retainer system was also abolished but, unlike slavery which was tackled with the Slavery Abolition Act, it was abolished through the promulgation of the Conscription Act of 124 R.E. (Rattanakosin Era) which abolished the social and economic commitments of the retainer system. In 1873, he promulgated an Act establishing Ho Rassadakornpipat as a Revenue office responsible for all taxation to enhance the efficiency of taxation and the performance of officers and tax collectors and to prevent corruption among the officers. In 1938, he promulgated the Treasury Act to reorganize the Treasury Department and make it more efficient. Monetary reform was also initiated with the emergence of banknotes. With his goal of making the Thai economy as developed as other countries, he set up the first Thai bank called the Siam Commercial Bank. Also, he worked on developing communication systems such as railways and canals for transportation.

King Rama VI

King Mongkut experimented with the establishment of democratic towns to practice democratic administration and established the Wild Tiger Corps.

King Rama VII

King Prajadhipok considered the granting of a constitution to the Thai people. In order to stimulate a political conscience, he promulgated the National Primary Education Act, reorganised the procedures for awarding royal scholarships to students for foreign education as well as scholarships for domestic education and established the Royal Thai Academy.