Alcanara (Arab., the bridge; anc, Norba CAesarea). I. A small town in Spanish Estre-madura, near the Portuguese frontier, on the left bank of the Tagus, in the province and 34 m. W. N. W. of Caceres; pop. about 4,500. A magnificent six-arch bridge, built across the Tagus in the reign of Trajan, was blown up by the British during the Peninsular war.

II. Knights of, a Spanish order deriving their origin from the knights of San Julian de Peyrero, a small body of valiant Christians in the 12th century who vowed continual war against the Moors. In 1215 Alcantara, which had been in possession of the Moors, was recovered by Alfonso IX., and the grand master of Calatrava being unable to undertake its defence, the duty was assigned to the brothers of San Julian, who changed their name to that of knights of Alcantara. In 1495, the grand master dying, Ferdinand the Catholic became administrator of the order, and united the office of grand master with the crown. The order as an organized body has since been abolished, and exists now only as a military order of merit. In addition to the usual vows of the monk-soldier, the knight of Alcantara was bound to maintain the immaculate conception of the Virgin. After 1540 a change was made in the statutes of the order, which permitted the knights to marry.