Muhammad Ali is widely regarded as one of the greatest athletes of the twentieth century. He was a boxer, philanthropist, and social activist. In 1960, Ali won an Olympic gold medal and in 1964, he was crowned world heavyweight boxing champion.
Ali won the heavyweight title twice more in the 1970s after being suspended for refusing military duty, winning famous fights against Joe Frazier and George Foreman along the way.

Ali, who was diagnosed with Parkinson's disease in 1984 and spent much of his time philanthropizing, was awarded the Presidential Medal of Freedom in 2005.

Ali was born on January 17, 1942, in Louisville, Kentucky. His birth name was Cassius Marcellus Clay Jr. Clay became a member of the Nation of Islam, a black Muslim organisation, in 1964. He first went by the name Cassius X before deciding on Muhammad Ali. During the 1970s, the boxer eventually converted to traditional Islam.

Ali was not ashamed to shout his own praises, sometimes referring to himself as "The Greatest." Before a fight, he was notorious for bragging about his abilities and using colourful words and metaphors. Ali once told reporters that he could "float like a butterfly, sting like a bee" in the boxing arena, which became one of his most famous quotes.