Muhammad Ali was born in Louisville, Kentucky in 1942; the older of two boys, he was named for his father, Cassius Marcellus Clay Sr. Growing up in the segregated South, Clay experienced firsthand the prejudice and discrimination that African Americans faced. When 12-year old Clay’s Schwinn bicycle was stolen, he reported the crime to police officer Joe Martin and vowed to get revenge on the culprits. Martin, who was also a boxing trainer, suggested Clay learn how to fight first and took him under his wing. Six weeks later, Clay won his first amateur bout. 

By age 18, the 6’ 3” Clay had racked up 100 victories against eight losses in amateur boxing, and started as a light heavyweight. He won the light heavyweight gold medal in the 1960 Summer Olympics in Rome and was heralded as an American hero. Clay made his professional boxing debut as a heavyweight in October 1960 and won in a six-round decision.

Clay became infamous for his bravado and his penchant for vocally belittling his opponents. Known from very early on in his career as the “Louisville Lip,” his rhymes, taunts, provocations and exclamations made up a larger-than-life persona. Often referring to himself as “The Greatest,” Clay was not afraid to sing his own praises and was known for boasting about his skills before a fight. Especially in the early years of his career, his audacious behavior made him controversial and disliked by most writers, many former champions, and much of the general public.

By late 1963, Clay was the top contender for Sonny Liston’s Heavyweight Champion title and the match was set for February 25, 1964 in Miami. Based on Clay’s weak performances against Jones and Cooper in his two previous fights and Liston’s defeat of former heavyweight champion Floyd Patterson in two first-round knockouts, the odds were set 7-1 against Clay.

Despite this, Clay taunted Liston, dubbing him the “big ugly bear” and saying he planned to “float like a butterfly, sting like a bee.” Clay dominated almost from the opening bell, peppering Liston with jabs and throwing fast combinations that seemed to bewilder the Big Bear. Liston quit in the corner after the sixth round, claiming a shoulder injury, and the world had a new heavyweight champion. In the ring after the fight, the new 22-year old champ roared, “I am the greatest!”

At a press conference just days later, Clay, who had been seen around Miami with controversial Nation of Islam member Malcolm X, confirmed the rumors of his conversion to Islam and declared he was changing his name to Cassius X, saying that Cassius Clay was his “slave name.” On March 6, 1964, Nation of Islam leader Elijah Muhammad bestowed on Clay the name of Muhammad Ali. Ali’s desire to rename himself initially met with widespread public resistance because the Nation of Islam was widely viewed by whites and even some African Americans as a black separatist religion with a propensity toward violence. Only a few journalists accepted the new name at that time. 

Muhammad Ali married Sonji Roi on August 14, 1964 in Gerry Indiana, but the relationship did not last and they divorced two years later amid conflict over Ali’s conversion to the Nation of Islam with Sonji claiming she was coerced into converting against her will.

Ali met Liston for a rematch to defend his heavyweight championship on May 25, 1965 in Lewiston, Maine. (see Ali vs. Liston) winning by knockout in the first round. Ali’s rematch against Liston was followed by a long string of victories against Floyd Patterson, George Chuvalo, Henry Cooper, Brian London, and Karl Mildenberger. Perhaps the most impressive fight during Ali’s reign as heavyweight champion during the late 1960s came against Cleveland Williams in November of 1966 when Ali landed more than100 punches and scored four knockdowns all while only being hit three times.

On April 28, 1967 Muhammad Ali refused induction into the US Army declaring himself a conscientious objector due to his religious beliefs. Ali was stripped of his championship title and banned from fighting by every athletic commission in the United States for three and a half years. Ali was criminally indicted and on June 20, 1967, was convicted of refusing induction into the armed forces and sentenced to five years in prison. Ali remained free on bail and spent four years before his conviction was overturned on a narrow procedural ground. Ali’s fight to stay out of the Vietnam War coupled with the growing civil rights movement made him an icon of dissension within American society and culture.

Ali returned to boxing in October of 1970 and, while unable to return to his former fitness, entered a period in his career with some of his most storied fights including the 1974 “Rumble in the Jungle” against George Foreman, and the 1975 “Thrilla in Manilla” against Joe Frazier. Ali continued to fight until 1981.

Muhammad Ali continued to practice Islam, eventually converting to Orthodox Islam and distancing himself from the Nation of Islam and its new leader Louis Farrakhan. Ali married four times and has nine children, including one who followed him into boxing, Laila Ali. Muhammad Ali suffers from Parkinson syndrome symptoms—slurred speech, slowed movements—from the many blows to the head sustained during his fighting career.