According to Roman ideas religion and its ministers were a part of the state and hence under the control of the government. When Constantine made Christianity a legal religion the state took the same attitude toward the new religion that it had toward the old. The emperor assumed control over the Christian clergy, and the view soon prevailed that they were officials of the state. Their duties, which were at first purely spiritual, were soon extended to secular matters. For obvious reasons the bishops were given an oversight over the administration of justice. During the invasions of the barbarians the secular functions of the bishops were greatly increased. Karl the Great made constant use of the bishops in the administration of his realm. By the tenth century many bishops were intrusted to a large extent with the secular government of their dioceses and so were full-fledged officials of the state. Attendance on diets was required of all officials, and eventually it was required only of officials. So it came about that the bishops especially formed an important part of the diet. Because of their learning they were indispensable to the emperor in conducting the affairs of his court and government; they naturally became his chief advisers. The bishops, then, have two sets of functions, the one spiritual, the other secular.
Through bequests and gifts from various sources the clergy, and especially the bishops and chief abbots, became great landholders. Many gave to the clergy for religious reasons, such as the salvation of their souls. But the emperors had still other motives: because of their office as emperor they were bound to build up the church; they felt it to be their duty to reward and to strengthen the clergy who were their faithful officials; and, furthermore, since they frequently met with opposition from the lay nobility, they thought it advisable to build up a strong ecclesiastical nobility to serve as a check upon the former.
As all other offices and relations became feudalized, so all the clergy underwent the same process. The bishops became the vassals of the emperor, and sustained the same feudal relations to him as did the lay nobility.
Since the bishops were both the officials and vassals of the emperor, it is certain that he would insist on having a voice in their election. Although the laws of the church did not permit this, nevertheless we find that from Karl the Great to Henry III all the emperors exercised the right of naming or appointing the bishops. Although at the time no objection was made to this action of the emperors, a new party had now arisen in the church which condemned it as simoniacal. This new party had its origin in the monastery of Cluny, from which it took its name. It was famous for the great reforms which it was trying to bring about. Now it was a part of the Cluniac programme that the church should be freed from all lay influence and that all ecclesiastical offices should be filled not by lay appointment but by election by the clergy (canonical election). Thus they gave simony a new meaning by declaring that every election which was not canonical was simoniacal. For simony was originally only the purchase or sale of any ecclesiastical office, but as the church, under the influence of this Cluniac party, developed her laws regarding canonical election and investiture, it came to be applied to every form of election and investiture other than canonical. The emperors had not only appointed the bishops, but they had also inducted them into their office. The induction into office was called investiture. Without it no one could fill the office to which he had been elected. To symbolize the power of the office the emperor presented the bishop with certain objects, such as a ring and a staff, which represented his spiritual authority over his diocese, and with a sceptre, which represented his temporal authority. The Cluniac party opposed all lay investiture and insisted that all the clergy should receive the symbols of their power from the church. But since the emperor’s temporal interests were so largely involved, he could not yield to the Cluniac demands without great loss of power. He could not tamely surrender to the pope the control of the bishops and their broad lands. Nor was it probable that the nobility would give up their rights (as patrons, etc.) to appoint the local clergy and to invest them with their office. So the struggle over investiture was long and bitter.
Lay investiture had already been prohibited by Nicholas II in the Lateran synod of 1059 but no steps had been taken to enforce the prohibition. Gregory VII renewed the prohibition and made it one of the prominent parts of his programme.
Although the opinion had long prevailed in the church that the celibate life, or chastity, was more holy than the married life, and therefore more becoming in the clergy, yet it was not uncommon for clergymen to marry. The Cluniac party regarded this state of affairs as especially blameworthy, and demanded that all the clergy be required to take the vow of perpetual chastity. In this, as in other respects, Gregory VII endeavored to carry out the Cluniac programme and so exerted himself to suppress clerical marriage, or, as the Cluniac party called it, clerical concubinage.
The following documents, nos. 60–64, illustrate the legislation of the church in regard to simony, celibacy, and investiture.
60. Prohibition of Simony and of the Marriage of the Clergy, 1074 A.D.
Sigebert of Gembloux, ad annum 1074; M. G. SS. folio, VI, p. 362.
Pope Gregory [VII] held a synod in which he anathematized all who were guilty of simony. He also forbade all clergy who were married to say mass, and all laymen were forbidden to be present when such a married priest should officiate. In this he seemed to many to act contrary to the decisions of the holy fathers who have declared that the sacraments of the church are neither made more effective by the good qualities, nor less effective by the sins, of the officiating priest, because it is the Holy Spirit who makes them effective.