More than 60 years ago, a bicycle thief in Louisville, Kentucky, unknowingly set in motion one of the most amazing sports careers in history.

An angry 12-year-old Cassius Clay went to a policeman on that day in 1954, vowing he would find the thief who took his bike and have his revenge. The policeman's advice was to learn to box first so Clay, who would later change his name to Muhammad Ali, went to a gym, where he learned quite well.

He would go on to be a record-setting heavyweight champion and also much more. Ali was handsome, bold and outspoken and became a symbol for black liberation as he stood up to the U.S. government by refusing to go into the Army for religious reasons.

As one of the best-known figures of the 20th century, Ali did not believe in modesty and proclaimed himself not only "the greatest" but "the double greatest."

He died on Friday at the age of 74 after suffering for more than three decades with Parkinson's syndrome, which stole his physical grace and killed his loquaciousness.

HBO Sports statement on the passing of Muhammad Ali:

"We join the rest of the world in mourning the passing of Muhammad Ali and celebrating the legacy of this unique man in unifying us through his acts and gifts.

“Ali's charisma, grace, and genius transcended all races, religions, nationalities, and generations. His spirit will inspire people forever.

"HBO is honored to have known Muhammad Ali as a fighter of beauty and a man of principle. We experienced the joy of working with him in support of initiatives he passionately cared about including, most importantly, his never-ending desire to teach tolerance and understanding of others to all people.

"Muhammad Ali was an icon and hero, father and friend, and beacon of hope for oppressed people throughout the world. He will be missed by all of those whose lives he touched. There are not enough bells to toll this loss."