The Daughter of Time

The Daughter of Time is a 1951 detective novel by Josephine Tey, concerning a modern police officer's investigation into the alleged crimes of King Richard III of England. It was the last book Tey published in her lifetime, shortly before her death. In 1990 it was voted number one in The Top 100 Crime Novels of All Time list compiled by the British Crime Writers' Association. 
Scotland Yard Inspector Alan Grant (a character who also appears in five other novels by the same author) is feeling bored while confined to bed in hospital with a broken leg. Marta Hallard, an actress friend of his, suggests he should amuse himself by researching a historical mystery. She brings him some pictures of historical characters, aware of Grant's interest in human faces. He becomes intrigued by a portrait of King Richard III. He prides himself on being able to read a person's character from his appearance, and King Richard seems to him a gentle, kind and wise man. Why is everyone so sure that he was a cruel murderer?