American chess master who, during his public career of less than two years, became the world's leading player. Acclaimed by some as the most brilliant player of all time, he was first to rely on the now-established principle of development before attack. (See chess: Development of theory (chess).)

Morphy learned chess at the age of 10. At 19 he was admitted to the Louisiana bar on condition that he not practice law until coming of age. After winning the first American chess championship tournament at New York City in 1857, he traveled to Europe, where he defeated Adolf Anderssen (Anderssen, Adolf) of Germany, the unofficial world champion, and every other master who would face him—the leading English player, Howard Staunton (Staunton, Howard), avoided a match with him. In Paris Morphy played blindfolded against eight strong players, winning six games and drawing two.

He returned to the United States in 1859 and issued a challenge, offering to face any player in the world at odds of pawn and move (where Morphy would play Black, thus giving up the first move, and would play minus one pawn). When there was no response, Morphy abandoned his public chess career. After an unsuccessful attempt to practice law, he gradually withdrew into a life of seclusion, marked by eccentric behaviour and delusions of persecution.