Ottoman military members and high-ranking politicians convicted by the Turkish courts-martial were transferred from Constantinople prisons to the Crown Colony of Malta on board of the SS Princess Ena and the SS HMS Benbow by the British forces, starting in 1919. Admiral Sir Somerset Gough-Calthorpe was in charge of the operation, together with Lord Curzon; they did so owing to the lack of transparency of the Turkish courts-martial. They were held there for three years, while searches were made of archives in Constantinople, London, Paris and Washington to find a way to put them in trial.[34] However, the war criminals were eventually released without trial and returned to Constantinople in 1921, in exchange for 22 British prisoners of war held by the government in Ankara, including a relative of Lord Curzon.