Leen Jansen was discovered as a boxer by soldiers who invited the harbor worker to join them for a few fights. Winning 109 out of his 134 amateur fights, Jansen qualified for the 1952 Olympics. In the quarter-finals, he was knocked out by eventual winner and future heavyweight world champion Floyd Patterson. Jansen immediately turned professional, eventually fighting 71 bouts through 1967, winning 60. He rarely fought outside of the Netherlands. Three times he successfully contested the Dutch middleweight title in 1954 and 1955. He also twice won the Dutch light-heavyweight title (1958-59), but failed to win the heavyweight title on two attempts. In 1980, he started a boxing school in St. Maartensdijk, where he continued to teach until shortly before his death at 83.
Netherlands