The formal inauguration of a bishop or abbot by the delivery of a ring and a staff had been customary with the emperors, kings, and princes of Europe, long before the establishment of the feudal system by Charlemagne, probably from the time of Clovis. And so far, if we bear in mind the relation of the Church to the State, and the original source of the privilege, it appears fair and right, though to a spiritual mind a most incongruous combination of temporal and spiritual powers, and ruinous to both. "When the early conquerors of the West," says Dean Waddington, "conferred territorial grants upon the church, the individuals who came to the enjoyment of them were obliged to present themselves at court, to swear allegiance to the king, and to receive from his hands some symbol, in proof that the temporalities were placed in their possession. The same ceremony, in fact, was imposed on the ecclesiastical as on the lay proprietor of royal fiefs, and it was called investiture. Afterward, when the princes had usurped the presentation to all valuable benefices, even to those which had not been derived from royal bounty, they introduced no distinction, founded on the different sources of the revenue, but continued to subject those whom they nominated to the same rank of allegiance, and the same ceremony of investiture, with the laity."
In the first fervor of conversion, the conquerors, from Constantine downwards, had been in the habit of bestowing a share of their newly-acquired property upon monasteries and churches; but the gifts of the successive dynasties were moderate, compared with the imperial house of Saxony. Under the German emperors church property accumulated rapidly, and to an enormous extent. "In the eleventh and twelfth centuries," says Greenwood, "freeholds in perpetuity were possessed by the churches to a very great extent. The bishops and abbots were enriched, not, as heretofore, by gifts of single plots of ground, or farms, but by grants of whole cities and towns, by cantons and counties. Thus Otho I. gave to the monastery of Magdeburg several boroughs, with their purlieus and the rural districts appertaining thereto. Otho II. granted three boroughs out of the imperial domain to the church of Aschaffenburg, with all the lands appurtenant. The terms of the conveyance do not appear to have differed at all from those used in secular grants of the like nature. And in practice, notwithstanding the different character and calling of the grantees, the same ideas of the nature and requirements of the grant appear to have been entertained by the spiritual as by the lay vassal. Thus bishops and abbots buckled on armor, mounted their chargers, and marched to the field, at the head of their sub-vassals and tenants, in discharge of the feudal duties incumbent upon their lands, nor could the latter be easily moved at all till led into action by their lawful chiefs.
"The great ecclesiastics, so far from objecting to these unprofessional demands, entered heartily into the sport of war, and bore themselves in the field with a degree of martial prowess which might become the bravest of the lay chivalry."
Such was the state of what may be called the christian constituency when Hildebrand issued his memorable edict against lay investitures; and such was the right or usage on the part of the crown of nominating and appointing to the greater ecclesiastical dignities and benefices. Hildebrand's scheme was to abolish entirely even the remotest claim of any interference, either for or against, on the part of the laity, in spiritual appointments, and to deprive the sovereign of the right of investiture, with which the law and custom of centuries had armed him, and which he regarded as the most precious prerogative of his crown. This was the question raised, the prize at issue, and the great battle to be fought, between the potentates of Europe and the meager monk in the Vatican. Gregory now addressed himself to the contest, the greatest by far ever undertaken single-handed in any age.