Bangkok Period

Within six months of the destruction of Ayudhya, Phya Taksin, a Chinese mercenary, and the remnants of the Ayudhya army drove off the invaders. He established a government at Thonburi and proclaimed himself King Taksin. His erratic and increasingly tyrannical behavior toward the end of his reign sparked a revolt in 1782. The government was overthrown and the king put to death.

Chao Phya Chakri (reigned 1782–1809) founded the dynasty that still rules, with Bangkok as its capital. The Thai kingdom was known as Siam in the Western world.

Early in the 19th century, European trade began to revive. In 1851 King Mongkut, an intelligent and progressive ruler, succeeded to the throne. He began a program of modernization and opened his country to Western influences. Mongkut sent for Mrs. Anna Leonowens, an Englishwoman, to tutor the royal children. (Mrs. Leonowens is the heroine of Margaret Landon's Anna and the King of Siam. ) His son, King Chulalongkorn (reigned 1868–1910), abolished slavery, modernized the laws, reorganized the educational system, and introduced a civil service system.

In the 20th century, Western technology and Western ideas continued to have an impact on life in Siam. The traditions of Western democracy were influential in the ferment that produced a revolution in 1932 that established a constitutional monarchy. King Prajadhipok (reigned 1925–35) was not opposed to constitutional government and continued as sovereign, but with limited powers. He soon disagreed with the revolt leaders, however, and abdicated in favor of his 10-year-old nephew, Ananda Mahidol. During World War II, Japanese troops occupied Siam.