Muhammad Ali was an American professional boxer and social activist. A global cultural icon, widely known by the nickname "the Greatest", he is often regarded as the greatest heavyweight boxer of all time. He held the Ring magazine heavyweight title from 1964 to 1970, was the undisputed champion from 1974 to 1978, and was the WBA and Ring heavyweight champion from 1978 to 1979. In 1999, he was named Sportsman of the Century by Sports Illustrated and the Sports Personality of the Century by the BBC.