The Knights of the Hospital assumed as their peculiar work the care of the sick.  The Begging Friars, as will be seen later, were distinguished by the importance which they attached to the rule of poverty; the Jesuits, by exalting the law of unquestioning obedience.  In view of the warlike character of the Middle Ages it is strange the soldier-monk did not appear earlier than he did.  The abbots, in many cases, were feudal lords with immense possessions which needed protection like secular property, but as this could not be secured by the arts of peace, we find traces of the union of the soldier and the monk before the distinct orders professing that character.  The immediate cause of such organizations was the crusades.  There were numerous societies of this character, some of them so far removed from the monastic type as scarcely to be ranked with monastic institutions.  One list mentions two hundred and seven of these Orders of Knighthood, comprising many varieties in theory and practice.  The most important were three,—­the Knights of the Hospital, or the Knights of St. John; the Knights Templars; and the Teutonic Knights.  The Hospitallers wore black mantles with white crosses, the Templars white mantles with red crosses, and the Teutonic Knights white mantles with black crosses.  The mantles were in fact the robe of the monk adorned with a cross.  The whole system was really a marriage of monasticism and chivalry, as Gibbon says:  “The firmest bulwark of Jerusalem was founded in the Knights of the Hospital and of the Temple, that strange association of monastic and military life.  The flower of the nobility of Europe aspired to wear the cross and profess the vows of these orders; their spirit and discipline were immortal.”

A passage in the Alexiad quoted in Walter Scott’s “Robert of Paris” reads:  “As for the multitude of those who advanced toward the great city let it be enough to say, that they were as the stars in the heaven or as the sand of the seashore.  They were in the words of Homer, as many as the leaves and flowers of spring.”  This figurative description is almost literally true.  Europe poured her men and her wealth into the East.  No one but an eye-witness can conceive of the vast amount of suffering endured by those fanatical multitudes as they roamed the streets of Jerusalem looking for shelter, or lay starving by the roadside on a bed of grass.

The term Hospitallers was applied to certain brotherhoods of monks and laymen.  While professing some monastic rule, the members of these societies devoted themselves solely to caring for the sick and the poor, the hospitals in those days being connected with the monasteries.