About Rocky Marciano:
Rocky Marciano is the only person to hold the heavyweight title without a bout tie or defeat during his entire career. Marciano defended his title six times, against Jersey Joe Walcott, Roland La Starza, Ezzard Charles (twice), Don Cockell, and Archie Moore. Marciano had a short, blazing career usually accustomed to pressure fighters, and at the end of it he retired with a record of 49-0, a record which stands to this day.