The defence of the Christian religion, and continued war against the Moors were the principal duties of the Knights.
The original costume consisted of a white coat-of-mail with a black pilgrim hood over it, and of a capoch and black scapulary (three inches wide) reaching down to the girdle.
The Knights were not only continually engaged in war with the infidels, in which they fought bravely for the cause of religion and the fatherland, but they frequently took part (against the express laws in their statutes), in the feuds of the Christians amongst themselves, by which means the Order acquired great power, authority and wealth.
Alphonso IX. having wisely availed himself of the despondency of the Moors, after their defeat in the battle of Las Navas de Tolosa, invaded in his turn their own territory, and took possession of the town of Alcantara on the Tagus, which he ceded in 1213 to the Order of Calatrava. The latter unable to defend alone so many places, and so distantly scattered frontiers, yielded the new conquest to the Knights of St. Julian, who transferred their seat to Alcantara, by which name they were thenceforth known. From a sense of gratitude, they submitted to the superintending authority of the Calatrava Knights, which they soon, however, found irksome to bear, and which consequently led to various disputes, until Pope Julius II. absolved them from it. Nor was the Order itself free from internal dissensions which, at last, assumed so violent a character as to lead, at a later period, to bloody feuds amongst the various parties who respectively elected Grand Masters of their own, and even presumed to interfere in the affairs of the State, and meddle with the concerns of the various Monarchs of the Spanish kingdoms. At last, in 1495, King Ferdinand V. obtained the consent of Pope Innocence VIII. to vest the Grand Mastership of the Order in the Spanish crown, by which means he increased his own revenue by 150,000 ducats,
