Henry Sara had been an anarchist before the war and was involved with anti-war and anti-imperialist groups around London between 1910-1916. He was one of the early Conscientious Objectors, arrested on the 13th April 1916. He was badly beaten and forced into uniform, enduring great brutality but consistently refusing to be cowed. He took an absolutist stance on military service and refused to make any compromise with either the Army or the Government. His several court martial appearances from 1916-19 were scenes of a passionate and forthright defence of the left-wing opposition to the "Captialist's War", but to no avail. He would serve six sentences in prison, each time released only to be called up to the army, court martialled and sent to prison. He was finally released on the 8th of April 1919. Soon afterwards he stood as a Communist candidate for elections around London and became known as a founder of British Trotskyism .