 Hospital work, the original work of the order, became once again its main concern.The Order's hospital and welfare activities, undertaken on a considerable scale in World War I, were greatly intensified and expanded in World War II under the Grand Master Fra' Ludovico Chigi Albani della Rovere (Grand Master 1931–1951).The Sovereign Military Hospitaller Order of Saint John of Jerusalem, of Rhodes and of Malta, better known as the Sovereign Military Order of Malta (SMOM), is a Roman Catholic lay religious order and the world's oldest surviving order of chivalry.