Yosef Lishansky was a Jewish paramilitary and a spy for the British in Ottoman Palestine. Upon his arrival in Palestine, Lishansky sought to join HaShomer but, denied membership, he founded a rival organization, HaMagen. Several years later, he joined the Jewish espionage organization, Nili. Lishansky was wanted by the Ottomans for his activities and was betrayed by HaShomer when he sought refuge with them. He escaped capture several times, but was eventually caught and sentenced to death in Damascus.

Hashomer was a Jewish defense organization in Palestine founded in April 1909. It was an outgrowth of the Bar-Giora group and was disbanded after the founding of the Haganah in 1920. Hashomer was responsible for guarding Jewish settlements in the Yishuv, freeing Jewish communities from dependence upon foreign consulates and Arab watchmen for their security. It was headed by a committee of three: Israel Shochat, Israel Giladi and Mendel Portugali.