Months after winning his first world championship, Clay joined the Nation of Islam. He adopted the name Muhammad in tribute to the prophet Muhammad, but the name he left behind was itself a tribute to another sort of fighter.

Like his boxing namesake, the original Cassius Marcellus Clay was born in Kentucky. That first Cassius Clay grew up to become a leading Abolitionist of the 19th century, and, like his cousin Senator Henry Clay, a politician. As for the middle name, Marcellus recognizes both a fighter and a leader. In the year 222 B.C., the Roman general Marcellus—nicknamed the sword of Rome—won the spoils of honor, the arms taken by a general who killed an enemy chief in single combat, for the third and last time in Roman history.