"O Regicidi" is a historical novel by the famous Portuguese writer Camilo Castelo-Branco. The book tells the story of the life and death of King Dinesh I of Portugal, who was killed in an assassination attempt. The author successfully combines facts and fiction to show the complex political and social situation of the country at that time. An exciting story with sculptural descriptions of characters and a vivid description of the environment will captivate the reader from the first pages. "About Regicide" is an exciting journey into the past that will leave an unforgettable impression.