So long as the church was poor, persecuted, and despised by the world, there were no purchasers for benefices. When a man lost his worldly status by becoming a Christian, and exposed himself to imprisonment and death, all trafficking in ecclesiastical preferments was unknown. But after the union of Church and State, and when the wealth of the world began to flow into the coffers of the church, there was a great temptation to enter the sacred order for the privileges and immunities which it secured. Simony thus became the inevitable consequence of the rich endowment of the greater Sees.
In the early days of episcopacy the bishop was elected by the clergy and the people of his diocese, but in process of time episcopal elections became so important; that the lay-lords, and even the sovereigns, were tempted to inferfere, and ultimately to establish and claim the privilege of positive appointment. Charlemagne himself set the example of advancing his natural sons to high ecclesiastical dignities. The privilege thus usurped was soon abused. The most important charges and offices were either bestowed on favorites, or publicly sold to the highest bidder, without regard for the interests of religion, sanctity of character, or even literary qualifications.
The universal feudal practice of making presents to the sovereign, or to the liege lord, at every act of promotion, was followed by the ecclesiastics. When a bishop or abbot died, it was usual, in the first place, to report the vacancy to the court, then the ring and the crosier of the deceased prelate or abbot were placed in the hands of the temporal superior. The bishop or abbot next appointed was bound by the general custom to present a gift or acknowledgment; this necessarily led to a transaction which assumed the character of a bargain and sale. The gift or offering, which at first was accepted as honorary and voluntary, was at length exacted as a price with unscrupulous rapacity. With this was connected the famous question of investiture. The ring, the symbol of his mystic marriage with his diocese; the staff, the scepter of his spiritual sway. This investiture conveyed the right to the temporal possessions or endowments of the benefice. It presumed not to consecrate, but permitted the consecrated person to execute his office in a certain defined sphere, and under the protection and guarantee of the civil power.
Many of the Sees were endowed with sovereign rights and royalties within their respective provinces. Bishops and abbeys had grown into principalities and governments, and to these ecclesiastical princes the largest share in the offices and councils of state had been entrusted. In the feudal system, bishops had become in every respect the equals of the secular nobles. "In every city," says Milman, "the bishop, if not the very first of men, was on a level with the first; without the city he was lord of the amplest domains. Archbishops almost equaled kings; for who would not have coveted the station and authority of a Hincmar, Archbishop of Rheims, rather than that of the feeble Carlovingian monarch?"
But the superior clergy were in no respect behind the laity in the corrupt practice of selling the spiritual offices within their patronage. Bishops and abbots sold their churches, without shame or remorse, that they might repay themselves for their outlay. That which had been obtained by unworthy means was employed for unworthy ends. Such was the fearful state of things both in Church and State, and such the unhallowed motives of men for taking holy orders, when Hildebrand sent forth his famous decree against all simoniacal practices, and against the whole right of investiture by the temporal sovereign, prince, noble, or any layman.