Imrich Lichtenfeld (26.5. 1910 – 9.1.1998)

Imi Sde-Or (formerly, Imrich Lichtenfeld) was born in 1910 to a Hungarian Jewish family in Budapest. He grew up in Bratislava, Slovakia where his father, Samuel Lichtenfeld was a Chief Inspector in the Bratislava Police Force.
As a former circus acrobat, Samuel Lichtenfeld owned a gymnasium where many activities were taught, including self-defense. Due to the influences of his father, Imi became a very successful boxer, wrestler and gymnast, competing at both national and international level.

Text is from http://krav-maga.com/imi-lichtenfeld/ where you can find more about history and development of Krav Maga.