List of world heavyweight boxing champions

At boxing’s beginning, the heavyweight division had no weight limit, and historically the weight class has gone with vague or no definition. During the 19th century, many heavyweights were 170 pounds or less, though others weighed considerably more. John L. Sullivan was the first widely recognized champion under Marquess of Queensberry rules. Known as the “Boston Strong Boy,” Sullivan weighed around 200 pounds when in shape, and helped transition the sport from its bare-knuckle era. Sullivan would be defeated for the title by “Gentleman” Jim Corbett over 21 rounds on September 7, 1892, the first heavyweight titleholder solely under Queensberry rules.