He managed the American athlete who 'literally changed the world of sports forever.' The man who became Muhammad Ali's boxing manager after Ali's conversion to Islam was Jabir Herbert Muhammad. The morning after winning the crown by knocking out Sonny Liston in 1964, then known as Cassius Clay, he confirmed that he had joined the Nation of Islam, a Muslim movement and soon became Muhammad Ali. Jabir Herbert Muhammad, a son of Elijah Muhammad, the leader of the Nation of Islam, became Ali's personal manager and later, in 1966, he began managing his boxing career. Jabir negotiated Ali's multimillion-dollar fights as his spiritual advisor. Ali, the three-time heavyweight champion, became one of the world's recognisable personalities while under Jabir's management. In 1988, with Ali suffering from Parkinson's syndrome, Jabir reflected on times when Ali proclaimed: 'I am the greatest.' Jabir built a mosque in Chicago, Masjid al-Faatir, on land he donated. Jabir Herbert Muhammad who was born in Detroit died of heart surgery in Chicago.