The Hospital of the Holy Ghost at Rome was the cradle of an order, which, beginning in the thirteenth century, spread throughout all the countries of Christendom, and whose incalculable services have been recognized by every historian of medicine. Speaking of the hospital itself, La Porte du Theil calls it "a useful establishment the most beautiful, the largest, and the best-ordered perhaps that exists at present, I say not in this queen of cities, I say in any civilized society of Europe". The famous Virchow of Berlin, an unbeliever, says, in speaking of the order: "It is just to recognize that it was reserved for the Roman Church, above all for Innocent III, not merely to tap this source of charity and Christian mercy in its plenitude, but to diffuse its beneficent flood in a methodical manner to every sphere of social life." Not that the idea of gathering together the sick in order that they might be assured of the care of a community of infirmanians was new in the Church. Nevertheless, a mistake must not be made on this point. The hospitium, the domus hospitalis, the xenodochium, which are mentioned before the thirteenth century, were in general only a refuge for alien (hospites, xenoi) travellers, poor wanderers, and pilgrims so numerous in the Middle Ages. The sick were treated at their homes in accordance with the words of Jesus Christ: "Infirmus (eram) et visitastis me" (I was sick, and you visited me. - Matt., xxv, 36). The first hospitals in the modern sense of the word found their origin in the monasteries under the name of infirmitoria. During the Frankish period, in the absence of a school of medicine, medical science found a refuge in the monasteries. The care of the sick formed part of the duties of charity imposed upon the monks. Hence there were two sorts of infirmaries, the infirmitorium fratrum within the clausura, and the infirmitorium pauperum or seculi without.

From the time of the crusades the hospitia of the Holy Land, those of the Hospitallers of St. John and the Teutonic Order (q. v.), were of a mixed character; founded for the reception of pilgrims to the Holy Places, they also served as hospitals for the sick. They became at the same time, as is well known, military in character, and to this circumstance may be credited the repeated attempts to give a military character to the Hospitallers of the Holy Ghost, although they have never earned arms nor had occasion to use them. Two circumstances led to the creation of the Hospitallers of the Holy Ghost by Innocent III: the example given in Provence by Guy de Montpellier, who established in his native town a lay community for the care of the sick under the patronage of the Holy Ghost (it is not known what caused him to choose this patronage; perhaps the Holy Ghost was chosen as the Spiritus amoris); the second cause was a foundation of Anglo-Saxon origin already existing on the banks of the Tiber. This was a simple hospitium founded in 715 by King Ina for his countrymen and known by the name of Hospitale S. Mariæ in Sassia, around which was formed a quarter called the Schola Saxonum. In the course of centuries the buildings had fallen to ruin, but the endowments were still available and were appropriated by the pope to the new institute. A first hospital building was erected in the same quarter, and Guy de Montpellier was called to Rome to organize the service of the sick.

In the beginning the institution was in the hands of laymen, Innocent III confining himself to attaching to it four clerics for spiritual duties, responsible only to the pope or his delegate. In return he endowed the institution with the most extensive privileges, hitherto reserved to the great monastic orders; exemption from all spiritual and temporal jurisdiction save his own, the right to build churches, to nominate chaplains, and to have their own cemeteries. The signal was given; everywhere there arose filial houses modelled after the mother-house, while houses already in existence hastened to seek affiliation in order to enjoy these great privileges; the filial houses swarmed in turn, and thus formed a network of colonies dependent immediately or mediately on the Holy Ghost at Rome, and enjoying the same privileges on condition of adopting the same rule, of submitting to periodical visitation, and of paying a light contribution to their metropolitan. At the end of the thirteenth century the order numbered in France more than 180 houses, and a century later nearly 400. In Germany the list drawn up by Virchow counts about 130 houses at the end of the fourteenth century. Another historian reaches a figure of 900 houses at the same period for the whole of Christendom, but he does not call it complete. The central authority, residing at Rome, was vested in a master-general, later called commander, a general chapter held each year at Pentecost, and the visitors delegated by the chapter.

An outburst of generosity responded to this display of Christian mercy; donations of every sort, in lands and revenues, poured in, which enriched the order and gave rise to a temporal administration modelled on that of the military orders. Thus their possessions were grouped into commanderies, which were soon invaded by laymen (many of them married), and thus arose the self-styled "Militia of the Holy Ghost". These lay knights assumed the revenues of these commanderies on condition of furnishing to the order an annual contribution analogous to the responsions of the military orders. This was an abuse to which Pius II put an end by appropriating these prebends of the Holy Ghost to a new order founded by him in 1459 under the name of Our Lady of Bethlehem. In 1476 Pope Sixtus IV decreed further that the commanderies should be given only to religious. As to the magisterial commandery at Rome, it was nearly always reserved for a prelate of the Roman Court. Under Guy de Montpellier and his early successors the two houses of Montpellier and Rome remained under the obedience of a common master general. When, later, two separate masters came to be appointed, it was decreed that the arch-hospital of Rome should collect the revenues of Italy, Sicily, England, and Hungary, and that the hospital of Montpellier should have jurisdiction over the houses of France and the other countries of Christendom.

Subsequent to this division of the order, confirmed in 1619 by Pope Paul V, Oliver of Terrada, invested with the dignity of general of the order in France, abused it to renew the Militia of the Holy Ghost. He proceeded to distribute brevets of knighthood to men of all classes, to laymen, often married, which gave rise to protests on the part of the religious of the order. Louis XIV first abolished this knighthood by an edict of 1672, which gave the goods of the Order of the Holy Ghost to the Order of Notre Dame de Mont-Carmel, founded to procure pensions for gentlemen who had served in his armies. The Knights of the Holy Ghost opposed the execution of this edict, the withdrawal of which they secured, in 1692, by means of a compromise according to which they pledged themselves to recruit and equip a regiment for the service of the king. However, the religious of the Order of the Holy Ghost opposed this edict in their turn, and in 1700, after lengthy proceedings, they finally secured victory in an edict which declared that the Order of the Holy Ghost was purely regular and in no way military. The buildings of the Arcispedale di Santo Spirito of Rome, which dated from the days of Sixtus IV (1471-84) are being reconstructed; they included a central hail, capable of containing 1000 beds, and decorated with frescoes, and special wards for contagious and for dangerous insane cases. A cloister was reserved for the physicians, surgeons, and infirmarians, who numbered more than a hundred. The church and the commander's palace date from the time of Paul III (1534-49). The annual revenue was estimated at 500,000 livres. Under the government of the popes, the Arcispedale was a catholic institution, that is to say a universal institution open to all Catholics, irrespective of country, fortune, or condition. To-day (1909) it is merely a municipal institution, reserved for the inhabitants of Rome.

A distinction must be drawn between this order and the Royal Order of the Holy Spirit founded in France by King Henry III, in 1578, to supersede the Order of St. Michael of Louis XI, which had fallen into discredit, and to commemorate his accession to the throne on Pentecost Sunday. This was a purely secular order of the court.

LEFÈBVRE, Des établissements charitables de Rome (Paris, 1860); VIRCHOW, Der Hospitaliter-Orden vom heiligen Geist (Berlin, 1877); BRUNE, Histoire de l'ordre hospitalier du St-Esprit (Paris, 1892); DE SMEDT, L'ordre hospitalier du St-Esprit in Revue des Questions Historiques (Paris, 1893); HÉLYOT, Histoire des ordres monastiques, II.

CH. MOELLER