Robert Fitzsimmons

Born in Cornwall, England on May 26, 1863, Robert Fitzsimmons only weighed 170 pounds at the height of his career. His shoulder width and overall prowess, however, allowed him to fight on a level with much larger opponents. Having gained fighting experience in New Zealand, Fitzsimmons arrived in the United States in 1890. His defeat of Jack Dempsey in 1891 earned him the world middleweight title.

In 1897, Fitzsimmons bested “Gentleman Jim” Corbett to clench the heavyweight title. To his title collection Fitzsimmons added the light heavyweight championship after defeating George Gardener in 1903. He was the first fighter to hold championship titles in three different weight classes. He retired in 1914 and passed away three years later.

Source: http://www.britannica.com/biography/Robert-Fitzsimmons