Are you familiar with Krav Maga? It's a military-based self-defence and fighting system.
I am not familiar with Krav Maga. Is this a sport?
It's more of a self-defense technique. It combines a bunch of different fighting styles: boxing and wrestling and street fighting.
Where was this technique first invented?
Krav Maga
Krav Maga (; , "lit." "contact combat") is a military self-defence and fighting system developed for the Israel Defense Forces (IDF) and Israeli security forces derived from a combination of techniques sourced from boxing, wrestling, aikido, judo and karate, along with realistic fight training. 
Krav Maga is known for its focus on real-world situations and its extreme efficiency. It was derived from the street-fighting experience of Hungarian-Israeli martial artist Imi Lichtenfeld, who made
came to the attention of European practitioners.
The concept rose to wide popularity during the 1960s and 1970s, with the development of Bruce Lee's Jeet Kune Do (1967) that uses aspects derived from various arts including Wing Chun and Western boxing; Kajukenbo (1947) which combines Karate, Judo/Jujitsu, Kenpo and Western Boxing; modern kickboxing styles that incorporate elements of Karate, Muay Thai and Western boxing, Krav Maga, an Israeli military combat and self-defense fighting system incorporating Western boxing, Muay Thai,