Shlomo Ben-Yosef was a member of the Revisionist Zionist underground group Irgun. He is most noted for his participation in an April 21, 1938, attack on a bus carrying Arab civilians, intended as a retaliation for an earlier attack by Arabs against Jews, and emblematic as a rejection of the establishment policy of Havlagah, or restraint. For this reason, and especially for having been the first Jew executed by the British authorities during the mandate period, Ben-Yosef became a martyr for the Revisionist cause and is commemorated by the State of Israel as one of 12 Olei Hagardom.

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.