
Since winning a gold medal in the 1960 Olympics, Muhammad Ali has never been far from the public eye. Take a look at the life and career of Ali, the three-time heavyweight boxing champion who called himself "The Greatest."

Ali, then known as Cassius Clay, poses in his hometown of Louisville, Kentucky, prior to his amateur boxing debut in 1954. He was 12 years old and 85 pounds. As an amateur, he won 100 out of 108 fights.

Ali rose to prominence at the 1960 Olympic Games in Rome, where he claimed a gold medal in the light-heavyweight division.

Ali boldly predicted it would take him five rounds to knock out British boxer Henry Cooper ahead of their bout in London in 1963. The fight was stopped in the fifth round as Cooper was bleeding heavily from a cut around his eye.

Patrick Power, 6, takes on Ali in the ring in 1963. Patrick was taking boxing lessons after getting bullied.

Ali poses for a picture with The Beatles in Miami, during the run-up to his heavyweight title fight against Sonny Liston in 1964.

Ali celebrates after defeating Liston in Miami on February 25, 1964. Upon becoming world heavyweight champion for the first time, Ali proclaimed, "I am the greatest!"

Ali relaxes after his win over Liston in 1964. At 22, he became the youngest boxer to take the heavyweight title from a reigning champion.

Civil rights activist Malcolm X, left, takes a picture of a tuxedo-clad Ali surrounded by jubilant fans in March 1964. Shortly after the Liston fight, Ali announced that he had joined the Nation of Islam and changed his name from Cassius Clay.

Known for being as quick with his mouth as he was with his hands, Ali often taunted his opponents. He famously said he could "float like a butterfly, sting like a bee."

Ali prepares to defend his heavyweight title in 1965.

Ali stands over Liston during their rematch in Lewiston, Maine, on May 25, 1965.

Ali eats at a restaurant in 1965.

The referee pushes Ali to a neutral corner as Floyd Patterson slumps to the canvas in November 1965. The fight was stopped at the end of the 12th round and Ali was declared the winner.

Ali signs an autograph for a fan in 1966.

Ali visits a children's home in London in May 1966.

Ali trains for his second fight against British champion Henry Cooper in May 1966.

British talk-show host Eamonn Andrews shares a laugh with Ali in May 1966.

Ali lands a right to the head of Brian London during their bout in London on August 6, 1966. Ali won by a knockout in the third round.

Ali looks in his hotel-room mirror in February 1967.

The referee counts as Ali looks down at Zora Folley during a championship fight in New York on March 23, 1967. Ali won by a knockout in the seventh round.

As a conscientious objector to the Vietnam War, Ali refused induction into the U.S. Army in April 1967. Here, top athletes from various sports gather to support Ali as he gives his reasons for rejecting the draft. Seated in the front row, from left to right, are Bill Russell, Ali, Jim Brown and Kareem Abdul-Jabbar.

Ali walks through the streets of New York with members of the Black Panther Party in September 1970. Ali was sentenced to five years in prison for his refusal to enter the draft, and he was also stripped of his boxing title. The U.S. Supreme Court overturned Ali's conviction in 1971, but by that time Ali had already become a figurehead of resistance and a hero to many. Related: Photographer fondly recalls his three days with Ali