Imre "Imi" Lichtenfeld (; 26 May 1910 – 9 January 1998), also known as Imi Sde-Or (), was a Hungarian-born Israeli martial artist. He is widely recognized for developing Krav Maga, an Israeli martial art. Early life Lichtenfeld was born on 26 May 1910 to a Hungarian-Jewish family in Budapest in the Austro-Hungarian Empire. He grew up in Pressburg (Pozsony, today's Bratislava). His family moved to Bratislava, where his father, Samuel Lichtenfeld, was a chief inspector on the Bratislava police force and a former circus acrobat. Lichtenfeld trained at the Hercules Gymnasium, which was owned by his father, who taught self-defense. Lichtenfeld was a successful swimmer, boxer, wrestler, and gymnast since his youth. He competed at national and international levels and was a champion and member of the Slovak National Wrestling Team. In 1928, he won the Slovak Youth Wrestling Championship, and in 1929, the adult championship in the light and middleweight divisions. That year, he also won the national boxing championship and an international gymnastics championship. Development of Krav Maga In the late 1930s, anti-Semitic riots threatened the Jewish population of Bratislava in Europe. Together with other Jewish boxers and wrestlers, Lichtenfeld helped to defend his Jewish neighborhood against fascist gangs. He quickly decided that sport has little in common with real combat and began developing a system of techniques for practical self-defense in life-threatening situations. In 1935, Lichtenfeld visited Mandatory Palestine with a team of Jewish wrestlers to participate in the Maccabiah Games but could not participate because of a broken rib that resulted from his training while en route. This led to the fundamental Krav Maga precept, 'do not get hurt while training.' Lichtenfeld returned to Czechoslovakia to face increasing anti-Semitic violence. Lichtenfeld organized a group of young Jews to protect his community. On the streets, he acquired hard-won experience and a crucial understanding of the differences between sport fighting and street fighting. He developed his fundamental self-defense principle: 'use natural movements and reactions' for defense, combined with an immediate and decisive counterattack. From this evolved the refined theory of 'simultaneous defense and attack' while 'never occupying two hands in the same defensive movement.' In 1940, Lichtenfeld fled the rise of Nazism in Slovakia, heading for Palestine on the Aliyah Bet vessel, Pencho, which shipwrecked on the Dodecanese Islands in the Aegean Sea. He reached Palestine in 1942 after serving with distinction in the British supervised Czechoslovak