Alcántara, a town on the Tagus whose name means here crossed by a bridge—cantara, and it is situated in the plain of Estremadura, a great field of conflict for the Moslems and Christians of Spain in the twelfth century. Alcántara was first conquered in 1167 by the King of Leon, Fernando II and fell again in 1172 into the hands of the fierce Jussuf, the third of the African Almohades and Alonzo of Leon, the son of Fernando, did not recover it until 1214.
The king resorted to military orders in order to defend this conquest because the border was exposed to many assaults. The Middle Ages had neither standing armies nor garrisons and military orders made up for this deficiency by combining military training with monastic stability. In 1214 Alcántara was first committed to the care of the Castilian Knights of Calatrava, who had recently given many proofs of their gallantry in the famous battle of Las Navas de Tolosa against the Almohades in 1212. Alonzo of Leon wished to found a special branch of this celebrated at Alcantara order for his realm. But four years later these Knights felt that the post was too far from their Castilian quarters. With the permission of the king, they give up this plan and transferred the castle to a peculiar Leonese order that was still in a formative stage, known as “Knights of St. Julian de Pereiro”.