It was closely affiliated with the pre-Israel Revisionist Zionist splinter group Irgun Zevai Leumi. Some of the most prominent politicians of Israel were Betarim in their youth, most notably prime ministers Yitzhak Shamir and Menachem Begin, an admirer of Jabotinsky. Across Europe, Betar militia played major roles in independently resisting Nazi forces and other various assaults on Jewish communities.