Muhammad Ali, 74, died Friday of a respiratory condition related to his Parkinson’s disease in an Arizona hospital, surrounded by family, according to a family spokesperson. He leaves behind several children and a boxing legacy that’s tough to lay a glove on.

Ali called himself “the greatest” and in many ways he was. He had learned to fight from a young age, reportedly starting boxing training when he was 12 to “whup” a boy who stole his bike. He went 100 and 5 in his amateur career.