Few human beings have been so deified in their own time. Then again, few humans have spent so much of their own time deifying themselves. “I am the greatest!” Muhammad Ali often declared — and eventually, most people came around to share his view. Born Cassius Clay in Louisville, Ky., he was a prankster from childhood, and merriment always seemed to be bubbling just below his surface, sweetening his braggadocio with just the right amount of sugar. After earning fame by winning the gold medal in light-heavyweight boxing at the Rome Olympics in 1960, he rose quickly to the top of the pro ranks, prancing and dancing in the ring as no boxer ever had before, yet able to throw and take punches of terrific force.
By 1964, the “Louisville Lip” was the world champ. A modern-day P.T. Barnum, Clay had reached into boxing’s then tawdry backroom and dragged his sport back into the limelight, laughing all the way. But there was more to Clay than the amusing rhymes and the silly pranks, as Americans soon discovered: that year he declared himself a member of the Nation of Islam, a controversial movement that sought to empower African Americans, christening himself Muhammad Ali.
(PHOTOS: Happy Birthday, Muhammad Ali: 70 Iconic Images for 70 Years)
Many Americans now denounced the brash boxer as a radical, and he was even more widely vilified when he refused to join the Army as the Vietnam War escalated. “I ain’t got no quarrel with them Viet Cong” he memorably declared. He was found guilty of refusing induction into the service in 1967, and the boxing commission quickly revoked his license to fight; the U.S. Supreme Court reversed that decision in 1971.
Ali was idle for more than three years when he was at the height of his powers. Yet when he returned, he expressed no bitterness, and he still had the old magic. He won back the title in 1974 by knocking out George Foreman in their fight in Zaïre — the “Rumble in the Jungle.” Another international bout, the 1975 “Thrilla in Manila,” in which he beat Joe Frazier, helped Ali become the best-known person on the planet — and, it seemed, the most beloved. In later years, his uncomplaining battle with Parkinson’s Disease further cemented his status as a global icon of courage, grace and good will.
This entry is excerpted from the new TIME book The 100 Most Influential People of All Time, which profiles spiritual icons, leaders, explorers, visionaries and cultural titans throughout human history. Available wherever books are sold and at time.com/100peoplebook