(Excerpted from Wikipedia)
Sir Thomas Malory (c. 1405 – March 14, 1471) was an English writer, the author or compiler of Le Morte d'Arthur. The antiquary John Leland (1506–1552) believed him to be Welsh, but most modern scholarship assumes that he was Sir Thomas Malory of Newbold Revel in Warwickshire. The surname appears in various spellings, including Maillorie, Mallory, Mallery, and Maleore. The name comes from the Old French adjective maleüré (from Latin male auguratus) meaning ill-omened or unfortunate.
Few facts are certain in Malory's history. He was probably born sometime around 1405 (though some scholars have suggested an earlier date). He died in March of 1471, less than two years after completing his lengthy book. Twice elected to a seat in Parliament of England, he also accrued a long list of criminal charges during the 1450s, including burglary, rape, sheep stealing, and attempting to ambush the Humphrey Stafford, 1st Duke of Buckingham. He escaped from jail on two occasions, once by fighting his way out with a variety of weapons and by swimming a moat. Malory was imprisoned at several locations in London, but he was occasilevelled against him. In the 1460s he was at least once pardoned by King Henry VI, but more often, he was specifically excluded from pardon by both Henry VI and his rival and successor, Edward IV. It can be construed from comments Malory makes at the ends of sections of his narrative that he composed at least part of his work while in prison. William Oldys speculates that he may have been a priest, based on Malory's description of himself in the colophon to Le Morte d'Arthur:
I pray you all, gentlemen and gentlewomen that readeth this book of Arthur and his knights, from the beginning to the ending, pray for me while I am alive, that God send me good deliverance, and when I am dead, I pray you all pray for my soul. For this book was ended the ninth year of the reign of King Edward the Fourth, by Sir Thomas Maleore, knight, as Jesu help him for His great might, as he is the servant of Jesu both day and night. (Malory p. 531)