a small town of Spain, in New Castile, situated on the river Guadiana, from which a well-known order of knights take their title. Long. 3° 90. W. Lat. 39° 4. N.

Knights of Calatrava, a military order in Spain, instituted by Sancho III. king of Castile, upon the following occasion. When that prince took the strong fort of Calatrava from the Moors of Andalusia, he gave it to the Templars, who, wanting courage to defend it, returned it to him again. Then Don Raymond, of the order of the Cistercians, accompanied with several persons of quality, made an offer to defend the place, which the king thereupon delivered up to them, and instituted that order. It increased so much under the reign of Alphonso, that the knights desired they might have a grand master, which was granted. Ferdinand and Isabella, with the consent of Pope Innocent VIII., afterwards reunited the grand mastership of Calatrava to the Spanish crown, so that the kings of Spain became perpetual administrators of this office.

The knights of Calatrava bear a cross gules, fleur-de-lisé with green. Their rule and habit were originally those of the Cistercians.