Cassius Clay was born on January 17th, 1942 in Kentucky.
Clay started training as a boxer at the age of 12, and by the age of 18, had already won a gold medal (as a light heavyweight fighter) at the 1960 Summer Olympics in Rome.
Following his conversion to Islam a few years later, he became Muhammad Ali.
Citing religious beliefs, and his opposition to the Vietnam War, Ali refused to be drafted to the army and was found guilty of draft evasion. He was stripped of his titles, asked to pay a fine, was sentenced to five years in jail, and couldn't box for years. The decision was overturned and Ali did not spend time behind bars.
When he eventually returned to the ring, he quickly made up for lost time by winning multiple titles in the 1970s.
His epic fights ("Fight of the Century", "The Rumble in the Jungle", "Thrilla in Manilla") against champs Sonny Liston, Joe Frazier, George Foreman, and Cleveland Williams, among others, helped secure his spot as one of the greatest fighters of the XXth century. He passed away last year.