The man considered the greatest boxer of all time inspired millions by standing up for his principles during the 1960s, and by always entertaining — in the boxing ring and in front of a microphone.
Muhammad Ali was an international superstar, loved as much for his humanity and wit as for his boxing skills. Now he's being mourned by everyone from former foes to the president.
A life that transected America's defining issues — race and religion; war and sports — also inspired writing that was nearly as captivating as the man himself.
The boxing legend's treatment could be complicated by symptoms of Parkinson's, the debilitating disease from which he's suffered for more than 30 years.
A new book, Blood Brothers: The Fatal Friendship Between Muhammad Ali and Malcolm X, explores how faith brought two African-American icons together and eventually tore their relationship apart.