“Float like a butterfly, sting like a bee”. Most people know these famous words from the greatest boxer of the 20^th century, Muhammad Ali. Ali began boxing at the age of 12. By the age of 18 he had already won a gold medal in the light heavyweight division at the 1960 Summer Olympics. Ali made his professional debut on October 29, 1960, winning a six-round decision over Tunney Hunsaker. From then until the end of 1963, Ali amassed a record of 19–0 with 15 wins by knockout.

 He was born Cassius Marcellus Clay Jr. and later changed his name to Muhammad Ali in 1964 after becoming a Muslim. In 1966, Ali refused to be drafted into the military because of his religious beliefs and ethical opposition to the Vietnam War. He was arrested and was found guilty of draft evasion and stripped of his boxing titles. He managed to stay out of prison while appealing the decision to the Supreme Court, where his conviction was overturned in 1971. He did not fight for nearly four years and lost a period of peak performance as an athlete. He continued to fight however and fought in many historical matches such as Sonny Liston and Joe Frazier. He remains one of the best boxers in history; in 1999 he was named Sportsman of the Century by Sports Illustrated as well as Sports Personality of the Century by BBC.