Muhammad Ali (/ɑːˈliː/;[2] born Cassius Marcellus Clay, Jr., January 17, 1942 – June 3, 2016[3]) was an Americanprofessional boxer, generally considered one of the greatestheavyweights in the history of the sport. Early in his career, Ali was known for being a controversial and polarizing figure both inside and outside the boxing ring.[4][5] He was one of the most recognized sports figures of the past 100 years, crowned "Sportsman of the Century" by Sports Illustrated and "Sports Personality of the Century" by the BBC.[6][7] He also wrote several best-selling books about his career, includingThe Greatest: My Own Story and The Soul of a Butterfly. Ali, originally known as Cassius Clay, began training at 12 years old and at the age of 22 won the world heavyweight championship in 1964 from Sonny Liston in a stunning upset. Shortly after that bout, Ali joined the Nation ...