Lay investiture, the appointment of Church officials by lay rulers, has existed in various forms throughout the history of Catholicism. During the Middle Ages, kings and emperors invested bishops and abbots with temporal power as vassals holding lands within imperial boundaries. Even popes did not always escape the control of secular rulers, who wished to appoint their own candidates to the highest position in the Church. Although the famous struggles concerning lay investiture between papacy and empire took place in the medieval era, state control over ecclesiastical appointments continued through subsequent centuries. A major incentive for the princes of Europe to embrace some form of Protestantism consisted in the power to dictate religion within their realms. In France, Gallicanism, the idea that civil authority holds a position at least equal to, if not greater than, papal jurisdiction, dominated Church and State relations during most of the 17th and 18th centuries and lasted even until the First Vatican Council. In more modern times Communist countries have continually aimed at supreme control over religion. The Chinese government, which has appointed bishops for the Patriotic (Communist) Church in China for decades, provides an obvious example. Only one bishop not officially recognized by the state remains, and he has suffered imprisonment since 1997. Far from remaining an issue only for the Middle Ages, lay investiture, as part of the whole question of the proper relationship between Church and State, still exists today.
In order to understand this controversy fully, however, one must return to the origins of Church and State relations in the late Roman empire. When the emperors Constantine and Licinius issued the Edict of Milan in A.D. 313, they granted toleration of all religions, including Catholicism, throughout the Roman Empire. Thereafter, Constantine and many of his successors involved themselves in religious questions, even the calling of councils. In response to the Arian heresy, Constantine convoked, most likely in accord with Pope St. Sylvester I, the Council of Nicaea. The pope did not attend the council himself but rather sent papal delegates to represent the papacy and to preside over the council. Because of the role of Constantine in convoking the council, the absence of St. Sylvester, and the attendance of Constantine during the conciliar sessions, confusion arose as to the religious role of the emperor. Certainly Constantine intended the good of the Church in attending the Council of Nicaea, as he enforced the decrees of the council against Arius and his supporters. Likewise, the emperor supported the Council of Arles and implemented its decrees against the Donatists in North Africa. However, people within the Roman Empire saw Constantine and subsequent emperors as religious as well as secular leaders.
This view coincided with previous concepts about rulers and religion not only during the history of the Roman Empire but also in other civilizations. The Egyptians considered their pharaohs divine, as did the Incas their rulers and the Japanese their emperors. The Roman emperors held the title Pontifex Maximus, or high priest. Other ancient peoples, such as the Babylonians and Persians, attributed divine favor to their kings. In almost all ancient civilizations the rulers controlled religion, which became either a part of the government or at least remained under the jurisdiction of the political leaders. Thus, a religious role for Constantine and his successors did not seem inappropriate to the people of the Roman Empire.
Imperial power over religion, however, proved problematic. Constantine did not fully comprehend the religious controversies of his time and, duped by the Arians, later tried to restore Arius and his followers to prominent positions within the Church. The situation became far worse under Constantine’s successors. Constantius II, a zealous Arian, convened councils to promote the heresy and forcibly spread Arianism throughout the empire, even imprisoning Pope Liberius and many Catholic bishops. Julian the Apostate, who reverted to paganism, actively attempted to revive the old Roman religion. Even Catholic emperors at times intervened in religious matters too much. Theodosius I, often called the Great, who together with Gratian issued the Edict of Uniformity in A.D. 380, which declared Catholicism the official religion of the Roman Empire and outlawed paganism and Arianism, periodically intervened in spiritual matters. Theodosius convoked the first Council of Constantinople on his own authority. Even though the emperor intended the good of the Church, Theodosius acted without the approval of Pope St. Damasus I. Thus, as in the case of Constantine, confusion arose regarding the religious power of the emperor.
Theodosius the Great left his rule to both of his sons, thus splitting the Roman Empire into two halves. Although previous emperors had also split the empire, this division marked the permanent partition. The eastern half became the Byzantine Empire, where the emperors continued to dominate religious matters to the extent of appointing the bishops of Constantinople and regarding the Church as a department of the government. Many historians use the term caesaropapist, supreme over both Church and State, to describe these emperors. From 537 to 752 the Byzantine rulers even held the right of approval over papal elections. This power meant that the new pope required imperial permission for the episcopal consecration to take place.
In the western half of the Roman Empire, the successors of Theodosius did not fully rule and instead became puppets for barbarian generals. These military men, however, could not command the obedience of other generals nor could they always protect Italy and Rome itself from invasions and sacks. As the western empire disintegrated during the fifth century, the people began to look to the popes and bishops to fill the void of political leadership. Pope St. Leo I, rather than the emperor or a general, turned away Attila the Hun from plundering Rome. Later, St. Leo also saved the Roman churches and works of art from the pillaging of Genseric and the Vandals. Similarly, St. Gregory the Great defended Rome from the Lombards by raising an army and signing a treaty with the Lombard king, in which the king recognized the pope’s role as temporal ruler of Rome. Also over the years the popes and bishops throughout the western half of the former Roman Empire had received land grants from the various secular rulers in return for support. This situation resulted in the higher clergy assuming both temporal and spiritual rule at the same time, and in many cases the bishops and abbots became vassals to the barbarian kings and their successors. Although ecclesiastical officials, as the most educated men of the time, provided the best candidates for both religious and secular positions, their dual role resulted in kings and emperors desiring to place men loyal to themselves and at the same time good politicians in power. Obviously, conflict would ensue between Church and State over selecting these candidates and investing them with their authority. Therein resided the origins of the lay investiture struggle.
As for the papacy, the popes needed an independent state to rule in order to remain free from the control of secular rulers. In addition to the property given by wealthy Italian families, the land and cities granted to Pope Stephen II by Pepin, the first Carolingian king of the Franks, in 754 and 756, gave temporal sovereignty to the papacy and thus ensured political freedom from both the Byzantine emperors and any Western kings. Pepin’s son Charlemagne added more Italian possessions to the Papal States in 787. The alliance and document agreed upon by Charlemagne and Pope Adrian I became the basis of relations between the papacy and the Carolingian as well as the German emperors for the ensuing centuries.
The establishment of the papacy as an independent political power, however, brought up the question of how the temporal rulers should treat the popes. This question of the relations of Church and State had arisen long before the eighth century. Over three hundred years earlier St. Augustine had written in The City of God that two societies existed: the City of God and the City of the World, both competing for mankind’s allegiance. St. Augustine argued that, although the City of the World could not demand loyalty from a Christian, who belonged ultimately to the kingdom of heaven, sin necessitated the existence of the State in order to maintain civil order. Therefore, men needed both Church and State, which must co-operate with each other.
At the end of the fifth century Pope St. Gelasius I defined the relationship between the clergy and secular rulers more clearly in a letter to Emperor Anastasius in 494: “There are two powers by which chiefly this world is ruled: the sacred authority of the priesthood and the authority of kings. And of these the authority of the priests is so much the weightier, as they must render before the tribunal of God an account even for the kings of men.” Two years later in his treatise On the Bond of Anathema St. Gelasius expressed the difference between the religious and temporal orders as regulated by God: “Thus He [Christ] distinguished between the offices of both powers according to their own proper activities and separate dignities, wanting his people to be saved by healthful humility and not carried away again by human pride, so that Christian emperors would need priests for attaining eternal life and priests would avail themselves of imperial regulations in the conduct of temporal affairs. In this fashion spiritual activity would be set apart from worldly encroachments and the ‘soldier of God’ (II Timothy 2:4) would not be involved in secular affairs, while on the other hand he who was involved in secular affairs would not seem to preside over divine matters. Thus the humility of each order would be preserved, neither being exalted by the subservience of the other, and each profession would be especially fitted for its appropriate functions.” Instead of one ruler exerting control over both the political and the religious realms, as had happened in most ancient civilizations, now with the establishment of the Catholic Church, two orders, one spiritual, the other temporal, must not only co-exist but also co-operate in separate yet overlapping spheres to bring about eternal salvation and civil tranquility.
As history unfolded, however, the possession of property by clergy and the subsequent dual role of bishops and abbots as religious and secular rulers caused a struggle to arise between Church and State over the power of investiture. Kings and emperors desired to bypass canonical elections and instead to appoint their own candidates to religious offices, even the papacy. This conflict engendered numerous crises for the Church throughout the Middle Ages and beyond.