He was one of the most revered monarchs of the country[citation needed].
Outside of Thailand, he is best known as the King in the 1951 musical and 1956 film The King and I, based on the 1946 film Anna and the King of Siam – in turn based on a 1944 novel by an American missionary about Anna Leonowens' years at his court, from 1862 to 1867.[1][2][3][4][5]
During his reign, the pressure of Western expansionism was felt for the first time in Siam. Mongkut embraced Western innovations and initiated the modernization of Siam, both in technology and culture—earning him the nickname "The Father of Science and Technology" in Siam.