A spiritual order of knights, with Cistercian rule, founded for the defense of the frontier of Castile against the Moors under Alfonso VIII., the Noble (l158-12l4). Its name at first was Order of San Julian del Pereiro ("of the pear-tree"), from a Castilian frontier citadel, the defense of which was entrusted to two brothers, Suarez and Gomez Barrientos, who with Bishop Ordonius (Ordosio) of Salamanca (1160-66) founded the order. When Alcantara in Estremadura was taken by King Alfonso IX. of Leon in 1213, the seat of the order was transferred to that place. Alfonso committed the defense of this important fortress at first to the knightly order of Calatrava (q.v.), but five years later he transferred the service to the Order of San Julian, which now (1218) took the name of the Order of Alcantara, being still subject, however, to the grand master of the Calatrava order. Taking advantage of a contested election, it separated from the Calatrava order, and elected its first independent grand master in the person of Diego Sanchez. During the subsequent struggles with the Moors, in which the Alcantara knights distinguished themselves by their bravery, they had on their flag the united arms of Leon and Castile, with a cross of the order and the ancient emblem of the pear-tree. The number of their commanderies in their days of prosperity was about fifty. When Juan de Zuñiga, the thirty-eighth grand master (1479-95) resigned his office to become archbishop of Seville, the grand-mastership passed to the king of Castile (Ferdinand the Catholic). With its independent existence the order lost more and more its spiritual character. In consequence of the disturbances in the Spanish monarchy, it was abolished in 1873, but was reestablished in 1874 as a purely military order of merit by Alfonso XII.