Sir Arthur Ignatius Conan Doyle KStJ, DL (22 May 1859 - 7 July 1930) was a British writer and physician, most noted for creating the fictional detective Sherlock Holmes and writing stories about him which are generally considered milestones in the field of crime fiction. He is also known for writing the fictional adventures of a second character he invented, Professor Challenger, and for popularising the mystery of the Mary Celeste. He was a prolific writer whose other works include fantasy and science fiction stories, plays, romances, poetry, nonfiction and historical novels.Doyle is often referred to as "Sir Arthur Conan Doyle" or simply "Conan Doyle" (implying that Conan is part of a compound surname, as opposed to his given middle name). His baptism entry in the register of St Mary's Cathedral, Edinburgh, gives "Arthur Ignatius Conan" as his given names and "Doyle" as his surname. It also names Michael Conan as his godfather.The cataloguers of the British Library and the Library of Congress treat "Doyle" alone as his surname.