A widowed Welsh schoolteacher, Anna, arrives in Bangkok with her young son Louis after being summoned to tutor the many children of King Mongkut. The two are introduced to the intimidating Kralahome, Siam's prime minister, who escorts them to the Royal Palace where they will live, although Anna had been promised her own house. The King ignores her objections and introduces her to his head wife, Lady Thiang. Anna also meets a recent concubine, a young Burmese named Tuptim, as well as the fifteen children she will tutor, including his son and heir Prince Chulalongkorn. In conversation with the other wives, Anna learns that Tuptim is in love with the man, Lun Tha, who brought her to Siam.