Muhammad Ali is the professional name of Cassius Marcellus Clay Jr., born January 17, 1942, in Louisville, Kentucky, and he remains widely recognized for his Olympic gold medal in light heavyweight boxing at the 1960 Rome Games and for transforming the sport as a three-line world heavyweight champion. This verified explainer outlines his confirmed legal name at birth, key career milestones, major fights, and enduring cultural influence, while clarifying common misconceptions. The following summary draws on authoritative records to provide a clear, durable reference that addresses searches about who Muhammad Ali was and what details are reliably documented.
Full birth name and early identity
At birth he was registered as Cassius Marcellus Clay Jr., the son of Cassius Marcellus Clay Sr. and Odessa O’Grady Clay. He maintained this legal name until he joined the Nation of Islam in the mid 1960s, at which time he publicly adopted Muhammad Ali. The transition reflected both personal conviction and the religious affiliation tied to the Nation of Islam, while his original birth name remains a verifiable biographic anchor used in legal, boxing, and historical records.
Why the name change matters
Switching from Cassius Clay to Muhammad Ali signaled a significant break with a surname linked to a slaveowner and aligned with his spiritual and political awakening. The new name became central to his public identity, civil rights stance, and global symbolism. Sources that list the former name help distinguish legal documents from the persona he cultivated as an athlete and activist.
Verified career and biographic milestones
Ali’s career is defined by specific, documented achievements, from amateur highlights to landmark professional bouts and social advocacy. Recognizing these verifiable events supports a durable understanding of his legacy without relying on rumor or speculation. The table below summarizes key confirmed details that answer what is concretely known about his path and impact.
| Attribute | Verified Detail | Source Type |
|---|---|---|
| Birth name | Cassius Marcellus Clay Jr. | Birth certificate, biographies |
| Date and place of birth | January 17, 1942, Louisville, Kentucky, USA | Vital records, census data |
| Olympic achievement | Light heavyweight gold medal, 1960 Rome Olympics | IOC results, news archives |
| World titles | Won lineal world heavyweight title three times (1964, 1974, 1978) | Boxing commissions, sanctioning bodies |
| Notable fights | Listened vs. Sonny Liston I and II, Fight of the Century vs. Joe Frazier, Thrilla in Manila vs. Joe Frazier | Promoter records, contemporary reports |
| Activism | Refused Vietnam War draft in 1967; civil rights advocacy throughout 1960s and 1970s | Court documents, speeches |
| Later roles | Diplomatic envoy, humanitarian work, philanthropy | Government archives, charitable records |
Key fights and their verified outcomes
Documented bouts form the core of Ali’s competitive record and help separate confirmed results from legend. Focusing on these verified events supports a fact-first understanding of his career arc.
- Sonny Liston I (February 25, 1964): Won world heavyweight title by seventh-round technical knockout.
- Sonny Liston II (May 25, 1965): Retained title via first-round knockout in controversial circumstances.
- Fight of the Century vs. Joe Frazier (March 8, 1971): Lost by unanimous decision in a historic, closely contested match.
- George Foreman, Rumble in the Jungle (October 30, 1974): Regained world title by seventh-round knockout using the rope-a-dope tactic.
- Joe Frazier, Thrilla in Manila (October 1, 1975): Won by technical knockout in a grueling, widely praised final encounter.
- Leon Spinks, February 15, 1978: Lost then regained world heavyweight title in a split decision within the same calendar year.
Athlete profile breakdown
Examining Ali through a structured profile helps emphasize durable facts over fluctuating narratives. This breakdown highlights dimensions that remain relevant for historical analysis, comparisons, and long-term reference.
| Category | Metric | Estimate or Range | Context |
|---|---|---|---|
| Physical | Height | 6 ft 3 in (190.5 cm) | Officially measured in weigh-in records |
| Physical | Reach | 78 in (198 cm) | Listed in bout documentation |
| Career | Professional record | 56 wins, 5 losses, 0 draws (with 36 knockouts) | Compiled by major sanctioning bodies and widely cited |
| Career | World title reigns | Three lineal heavyweight championships | Recognized by historical boxing authorities |
| Social | Key cause | Civil rights and opposition to the Vietnam War | Documented in speeches, court cases, and policy responses |
Common name and terminology clarifications
Because Ali is known by multiple names and labels, it can be useful to clarify how and why these terms are used in reliable sources.
- Cassius Clay: Refers to his pre-Nation-of-Islam legal name; appears in early newspaper archives and legal transcripts.
- Muhammad Ali: The name he adopted after joining the Nation of Islam; used in most post-1964 sources and contemporary references.
- The Greatest: A widely recognized epithet tied to his boxing achievements and cultural confidence; reflects public perception rather than a formal title.
- Heavyweight champion: Denotes his division and status; he held lineal recognition across three reigns under different sanctioning contexts.
Relationship between name identity and public legacy
Ali’s choice to change his name was tightly connected to his public statements on race, religion, and resistance. By adopting a name rooted in Islam and rejecting a surname associated with enslavement, he framed his identity as part of a broader movement. This relationship between personal naming and public legacy is consistently documented in interviews, legal records, and institutional acknowledgments. Reliable sources treat both his birth name and his adopted name as part of a coherent narrative that emphasizes agency and conviction.
Status and clarification on records
Some confusion arises from variant spellings, informal renderings, and nostalgic references that differ from formal documentation. Verified records, such as birth certificates, Olympic and boxing commission files, and court materials, consistently support the details outlined here. When evaluating claims about Muhammad Ali, checking against primary documents helps filter rumor from confirmed fact and supports an accurate, long-lasting understanding of his life and career.