In the 1922 census of Palestine, conducted by the British Mandate authorities, al-Mazar had a population of 223, all Muslims, increasing slightly in the 1931 census to 257, still all Muslims, in a total of 62 inhabited houses. The village was home to Sheik Farhan al Sadi, a prominent leader in the 1936 Arab revolt in Palestine. In 1937, at the age of 75, he was executed by the British authorities for his participation in the revolt.