Avraham Stern, alias Yair, was one of the leaders of the Jewish paramilitary organization Irgun. In September 1940, he founded a breakaway militant Zionist group named Lehi, called the "Stern Gang" by the British authorities and by the mainstream in the Yishuv Jewish establishment. The group referred to its members as terrorists and admitted to having carried out terrorist attacks.

The Irgun, or Etzel, was a Zionist paramilitary organization that operated in Mandatory Palestine between 1931 and 1948. It was an offshoot of the older and larger Jewish paramilitary organization Haganah. The Irgun has been viewed as a terrorist organization or organization which carried out terrorist acts.