Olei Hagardom (Hebrew: "Those hanged in the gallows", עולי הגרדום) refers to members of the two Jewish Revisionist pre-state underground organisations Irgun and Lehi, who were tried in British Mandate courts and sentenced to death by hanging, most of them in Acre prison. There were 12 Olei Hagardom.
The term does not include members of the Nili organisation hanged by the Ottoman government during World War I.
The British Mandate for Palestine was an instrument of government instituted by the League of Nations for the administration of territories formerly under the rule of the Ottoman Empire. British rule lasted from 1917-1948.
During the 1936–1939 Arab revolt, the militant group known as the Irgun embarked on an intensive armed campaign against Arab targets. Later British targets were added also. With the outbreak of World War II, militant actions against the British were halted, but one of the leaders of the group, Avraham Stern, insisted that the fight must go on, leading to a split in the Irgun which led to the formation of a new group, Lehi (also known as the Stern Gang). In 1944, the Irgun, now headed by Menachem Begin rejoined the fight against the British. After the end of World War II, the larger Haganah joined the fight within a union called the Jewish Resistance Movement, which lasted for just about ten months, from October 1945 until August 1946.