The real King Mongkut was paralyzed on one side of his face.This fact is completely omitted from the film.
This story is inspired by the novel "Anna and the King of Siam" by Margaret Landon, which was a best-seller in 1944. The book was inspired by the memoirs and books of Anna Harriet Leonowens, who worked as an English teacher in the royal palace of the King of Siam (Thailand). Much of what Leonowens had written over the years had been invented by her, including some of the cruelties she claimed to have witnessed. Many years later, she met with the son and then-King of Siam, who asked her why she had written such lies about his father, but she insisted they were true. She was known for writing about a three-year visit to Egypt that never happened, claiming in one book that gibberish was Thai, elevating her late husband's rank from private to major, and saying that she was born in England (she was born in India, and was one quarter Indian). According to testimony by one of Tuptim's daughters many years later, she also invented Tuptim's fate.
The film was banned in Thailand because of historical inaccuracies about the King of Siam and the time period of the film.
The movie was filmed in Malaysia because the Thai government refused to give permission to film in Thailand. Despite several script revisions, the Thai authorities maintained that the film had too many historical inaccuracies.