A favorite expression of Thais is "mai pen rai," meaning "never mind; it doesn't matter; everything will be all right," an expression which says much about the agreeable Thai temperament. And one of the most popular stories about Thailand is Anna and the King of Siam by Margaret Landon, on which the musical comedy and movie The King and I were based. But let a foreigner speak admiringly of Anna and the King of Siam or The King and I, and there will be no utterance of "mai pen rai." In Thailand's constitutional monarchy the King is held in high esteem. The subject of these works was Rama IV, King of Siam from 1851 to 1868, a remarkable, farsighted leader who opened the doors of his kingdom to new ideas in science, education, and historical research. Thais deeply resent the portrayal of their beloved Rama IV in The King and I as something of a buffoon, and they hotly dispute the historical accuracy of Anna and the King of Siam.