Gershon Ben Keren is a 5th Degree Black Belt and Head of System for Krav Maga Yashir. He has been training in Krav Maga since 1994, in both Israel and Europe. In his over 25 years of experience, he has trained with many different trainers and associations, including some of the Israeli Defense Forces' most elite Close Combat/Krav Maga instructors. In 2010, he was inducted into the Museum of Israeli Martial Arts by Dr. Dennis Hanover.

Having worked in the security sector, as an operative, trainer and consultant, his emphasis is on violence mitigation, prediction, and avoidance. His real world experience, coupled with his academic background (Master's Degree in Psychology and continued Post-Graduate study in Criminology and Criminal Psychology), informs the reality-based self-defense training that he provides to individuals, corporations, and agencies. He lives in Boston, where he runs his full-time school, and corporate services, as well as free women's self-defense/self-protection training, through Krav Maga Yashir Boston.