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The Rise of the Medieval Church

Picture of a statue of St Peter

On 11 November 1215, in the Lateran Palace in Rome, the largest council of church leaders the world had yet witnessed convened.  400 bishops, 800 abbots along with observers from the Eastern Patriarchs were all there at the behest of one man.  That man was Pope Innocent III. 

This council issued a wide range of canons, governing everything from tackling clerical corruption, ensuring correct monastic discipline and regulating the lives of the laity.  How often the laity ought to make confession, what the church should teach them, the conducting of their marriages, whom they could to marry.  The list of rulings goes on. 

The range of canons, and the fact of their adoption across western and central Europe, demonstrates the enormous power of the medieval Church.

Church power even extended beyond the spiritual world into the secular.  As Innocent III himself wrote, a few years earlier:

“Now just as the moon derives its light from the sun and is indeed lower than it in quantity and quality, in position and in power, so too the royal power derives the splendour of its dignity from the pontifical authority.” 

Innocent III, 1198

But this had not always been the case. 

Bishop of Rome

In the late Roman world, the pope had been just one of several senior bishops in the empire.   The See of Rome enjoyed prestige and respect but held no real power.  People consulted Rome for religious advice only as and when they felt like it.  And, most important of all, the pope was not the head of the Church – the emperor occupied that role.  The pope was nothing more than just one of several senior religious advisors that the emperor might choose to consult (or not).

So, what had happened between 476, when the western Empire fell, and Fourth Lateran Council of 1215?  How had the medieval Church become so dominant in western and central European society?

The late Roman church

When the Emperor Constantine converted to Christianity, the organisation of the church was very informal.  Local Christian communities each followed their own traditions and patterns of behaviour in terms of organisation, teaching , the conducting of services and so on.  Certainly they shared a common set of fundamental beliefs, but if you were to attend a church service in Alexandria and a service in Ravenna, you’d likely encounter two very different experiences.

Depiction of the first Nicean council
The First Nicaean Council of 325

Now that Christianity was the Roman state religion it would have to become, well, more Roman.  That meant becoming better organised and more consistent in terms of what it was teaching (and how it was taught).  With this in mind, Constantine convened the First Council of Nicaea in 325.  Churchmen from all over the empire came to meet and discuss the big issues of the day – agreeing on what precisely was the nature of God, when Easter should be celebrated and what Christians had to believe in order to be regarded as Christians.

The Nicene Creed

This first council famously produced the Nicene Creed, a statement of fundamental belief at the heart of the Christian faith.  In 325 the original creed read as follows:

We believe in one God, the Father almighty, maker of all things visible and invisible; And in one Lord, Jesus Christ, the Son of God, begotten from the Father, only-begotten, that is, from the substance of the Father, God from God, light from light, true God from true God, begotten not made, of one substance with the Father, through Whom all things came into being, things in heaven and things on earth, Who because of us men and because of our salvation came down, and became incarnate and became man, and suffered, and rose again on the third day, and ascended to the heavens, and will come to judge the living and dead, And in the Holy Spirit.

But as for those who say, There was when He was not, and, Before being born He was not, and that He came into existence out of nothing, or who assert that the Son of God is of a different hypostasis or substance, or created, or is subject to alteration or change – these the Catholic and apostolic Church anathematizes.

The original wording of the Nicene Creed, 325

A more consistent religion

Much of this might seem like pretty fundamental and obvious stuff to us now, but prior to 325 not all Christians would have agreed with it.  Arian Christians believed that Christ had not come into existence until the time of his birth and that his nature was mutable and subject to change.  This is just one (very prominent) example of how different communities of Christians had evolved to adopt subtly (and sometimes significantly) different beliefs.

From 325 onwards the Roman emperors would bring a greater degree of consistency to the faith.  When difficult theological questions arose, the emperor would call a council, bring together his senior churchmen, listen to their opinions and arguments and arrive at a ruling.

The early popes

The popes of the Roman empire were nothing more than senior bishops.  Rome was closely associated with Saint Peter, who had been the first Roman bishop.  It was also associated with Saint Paul, who had been martyred (and probably buried) there.  Rome’s association with these two important saints gave the Roman See a special prestige recognised by the first council.

The bishop of Rome had now officially acquired a senior status that outranked most other bishops (but not all).  It consequently acquired a greater significance as a place of appeal for the hearing and resolution of religious disputes.  This began quite informally – a churchman would write to the pope asking his opinion on a particular question.  The pope would then write back giving his opinion.  In the time of Innocent I (401-17) this became more formalised when the pope began to issue ‘decretals’.  Decretals, modelled on the imperial rescript, outlined a legal question at the top of a document with a ruling provided in the second part.

Greater influence

Sometimes (although not often at this time) a community that was not formally part of the Roman See might ask a pope to provide an opinion .  Communities in places like Gaul, Spain and North Africa would all occasionally seek the pope’s advice.

However, the importance of the decretals in the late roman world should not be overstated.  A pope would only ever issue decretals in response to a request for an opinion.  Unless someone asked for a decretal, none would be issued.  It was an entirely reactive process on the part of the papacy.

In imperial times, the papacy had no formal powers of enforcement for its rulings. The emperor had the final say and provided the means of enforcement if (and only if) the emperor decided that this was necessary.

The fall of Rome

When the western empire fell in 476, Rome found itself cut off from the old imperial structures in which it had operated.  Initially an Ostrogoth successor state ruled Italy, but the Ostrogoths were Arian Christians who did not acknowledge the Nicene Creed.  Fortunately for the papacy, King Theodoric was a tolerant man when it came to religion and did nothing to impose Arianism on Italy. 

If anything, the papacy was, for a while, able to operate a little more independently than it had before.  Unlike all the other major Christian centres it was not subject to the direct rule of the eastern emperor.  This gave Rome a little freedom to dare to dissent from the opinions of that emperor – but only a little and not for long.


During this period however, the papacy felt free enough from imperial control to openly express the idea that the church represented a power in its own right, operating independently from the state.  Pope Gelasius I wrote to emperor Anastasius:

“There are two powers which for the most part control this world, the sacred authority of priests and the might of kings. Of these two the office of priests is greater in as much as they must give account even for kings to the Lord at the divine judgement.” 

Pope Gelaisus I

However, Gelasius was able to write this from the relative safety of an Italy controlled by Theodoric the Goth.  He knew full well that he was beyond the reach of Emperor Anastasius’ secular powers, should the emperor disapprove of his opinions.

During this time we also see the beginnings of western church scholarship.  Dionysius Exiguus would undertake important work in the development of canon law, collecting together canons from past ecumenical councils and papal decretals in a single volume of works.  The creation of this work and its dissemination would enhance Rome’s reputation as a source of religious authority.

The Byzantine period

In the mid-sixth century the eastern emperor, Justinian I, conquered Italy, absorbing it back within the Roman empire (albeit the eastern empire this time).  Rome was now back under imperial control and would remain so for most of the next two centuries.

It would be Justinian who would formalise the organisation of the church one step further by his creation of the Pentarchy.  Justinian set down in law that five senior churchmen should govern the Christian world.  These were the pope and the patriarchs of Constantinople, Alexandria, Jerusalem and Antioch. The emperor, of course, remained the head of the church but the pope was now officially the highest ranking of the top five churchmen in the empire.

Early in this period Pope Gregory I (later known as Gregory the Great) reformed church liturgy and produced a considerable volume of scholarship.  His writings covered sermons, advice on pastoral care, studies of biblical stories such as the life of Job as well as hundreds of letters.  It would be Pope Gregory who would send missionaries to England to convert the pagan Anglo-Saxons. 

Some might even credit Gregory with founding the medieval Church.  However, at this time the papacy still lacked the formal authority it would come to wield by the time of Innocent III.  For all his achievements, Gregory still answered to an emperor in Constantinople.

Imperial decline

The Arab conquests of the seventh century would greatly reduce the power of the eastern empire.  With its territories greatly reduced, so too were imperial tax revenues.  Such remaining political and military resources as the empire possessed increasingly had to be concentrated in the east.  This situation allowed the western provinces of the empire greater autonomy.  The Roman See benefited from this transition in so far as it found itself increasingly in direct control of the resources of the city of Rome itself.

During the time of Gregory II (715-731) the eastern empire was in crisis.  The emperor sought to introduce major tax rises to pay for the war with the Arabs.  It was a move that was desperately unpopular with the local secular powers in Italy who encouraged Gregory to defy the emperor and refuse to pay.  The emperor despatched an army to bring the pope to heel in 725 but, with local Italian support, they repelled the Byzantine forces.  At this time, perhaps more than any other, saw the birth of an independent state of Rome.

However, the papacy was not yet truly independent.  Instead of being controlled by an emperor, the papacy was now beholden to powerful local Italian lords.  Whilst they would help ensure the independence of the Papal state, they would also strive to have a significant say in who got to be Pope in the first place.

Independence from the eastern empire brought with it dangers of its own.  Powerful local Italian states posed a potential threat to Rome, especially the kings of the Lombards in the north.

The Carolingians

In 751, the Lombard king Aistulf took control of Ravenna and threatened to take control of Rome as well. In response, Pope Stephen II visited the Frankish king, Pepin III, to ask for his aid.

Over the next few decades, the power of the northern Franks would reach its zenith under the leadership of Pepin’s son – Charlemagne.  Charlemagne established a new empire in the west, encompassing France, northern Italy, Germany, and parts of northern Spain.  The old Roman empire disappeared and a new Frankish, Carolingian, one now took its place.

Map of the Carolingian and Byzantine Empires in 814
The two great European empires in the early C9th – Byzantine (purple) and Carolingian (yellow)

Charlemagne, as it turned out, took his duties as emperor very seriously.  One area he took a close personal interest in was religion.  Charlemagne believed it was his duty to ensure the spiritual wellbeing of his subjects.  And he understood that the Church would need to play a part in this. 

By sheer chance of geography, Charlemagne’s empire had inherited just one of the five key centres of the Christian faith as established by Justinian – Rome.  Rome, then, would be central to Charlemagne’s plans.  To this end, the new emperor endowed Rome with significant lands and wealth.  The increase in papal income was enormous.  But this would not prove to be Charlemagne’s most significant impact on the development of the western church.


Christianity in western Europe at this time had a number of problems that needed addressing.  The first was that western Europe did not really use Greek (the lingua-franca of the eastern Empire).  That was a problem because a significant volume of religious work was only available in Greek.  Often only a relatively few copies of important works in Latin, the written language of western Europe, were available. 

Another problem was that the written forms of Latin that had evolved after the fall of Rome were often very far from the original classical Latin.  This meant that many documents were littered with translation errors or used a form of Latin that was not universally readable (or which was open to misinterpretation).

A final problem was that church law, papal decretals, council rulings and such existed nowhere in a single complete form.  The old Dionysius Exiguus was now hopelessly out of date.  A confusing array of different documents scattered across the western world had led to inconsistency of religious practice across the new empire.


Charlemagne determined to put this to rights.  So, in 789 he issued his template for the religious health of his empire, the Admonitio Generalis.  In this document he charged the western Church with implementing a rigorous programme of scholarship known as ‘Correctio’.  Religious writings, rulings and points of doctrine would be collated; contradictions and mistranslations corrected; and a more coherent body of up-to-date scholarship created.  And all in grammatically correct classical Latin.

Charlemagne mustered together all the most capable religious scholars operating across his empire for the task.  These scholars set to work translating, copying and collating.  They didn’t just limit themselves to religious works but also created new copies of older classical Latin works unrelated to religion.  All this served to improve their knowledge of the Latin language and to instil a more rigorous scholarly culture within the Church.

The Rule of Benedict, governing monastic life, was updated to place a greater emphasis on study and was more strictly applied across Europe.  An important scholar of this period, Paul the Deacon, created a work listing a series of readings and sermons best suited for use at each of the different Christian festivals throughout the year.  Also, at this time, episcopal statutes began to appear in increasing numbers.  A standardised form of classical Latin gradually spread across the entire empire.  It became, and would remain, the primary language of written scholarship in western Europe throughout the Middle Ages.

Pseudo Isadore

At some point in the mid-ninth century just as Charlemagne’s grandchildren were carving up the Carolingian empire, a collection of documents known as ‘Pseudo Isadore’ appeared.

The name itself is misleading and largely unimportant.  No one really knows who wrote Pseudo Isadore, although some think it was most likely to have been a scholar working in Rheims.  Some of it was a genuine and authentic translation and collation of earlier works.  Part of it was updating with ‘embellishments’, based on genuine original documents but with a certain amount of dramatic licence thrown in.  And some of it was nothing more nor less than outright forgery.

Pseudo Isadore was skilfully put together, and a convincing piece of work.  It ticked all the right boxes in terms of what it purported to be.  And it contained within it a message that many churchmen of the time liked the look of.  The pick of the collection was a work entitled The Donation of Constantine.  It claimed to be a copy of the emperor’s grant to the papacy of full authority over the entire western Church.  To add colour to this ‘grant’, the forger created a number of pre-Nicaean decretals, designed to show that popes had been issuing religious rulings since the earliest Christian times.  It was complete fiction, but very convincingly done.

Unintended consequences

These forgeries served to bolster the power and authority of the Holy See by creating false precedents dating back to early Roman times.  Most interestingly, these forgeries were locally created in Rheims, and it seems that the Holy See itself had nothing to do with them. 

Pseudo Isadore also just so happened to contain within in it copies of old Church rulings which made it far harder for bishops to be replaced or dismissed.  It claimed bishops threatened with dismissal had the right to appeal directly to the pope.  The forger’s purpose then was not so much to bolster papal authority but to greatly enhance the job security of bishops.  A local archbishop, up to this time, could easily get rid of a bishop he didn’t like.  However, if the distant Roman See became involved, that made the whole process far more bureaucratic and difficult.

This was likely the forger’s main aim – making bishops more independent of local religious authority.  To achieve this, it was necessary to demonstrate that the papacy, and not the local archbishop, had the final say on who should or should not be a bishop.  Thus, Pseudo Isadore had the incidental consequence of bolstering papal authority in the longer term.

Pseudo Isadore proved very popular at the time and, as a result, did much to spread the idea of supreme papal authority across western Europe.  It may have been a forgery, but it was nevertheless an important step in enhancing and bolstering the authority of the Holy See.

Carolingian decline

As long as the Carolingian empire lasted, the papacy was able to exert significant influence over the church in western Europe.  However, although the papacy was more powerful than it had ever been before, it was still beholden to an imperial authority.  At the end of the day, Charlemagne and his successors reserved the right to have the final say in religious matters.  It was not the pope’s Correctio, but Charlemagne’s.

As the Carolingian empire began to disintegrate in the latter part of the ninth century, so too did the mechanisms necessary to control the Church across western Europe.  The papacy remained and, thanks to Correctio, a thriving tradition of scholarship was now embedded within the western Church.  However, the secular levers of control, enforcement and administration were gone.

What remained was a powerful and wealthy papal state, centred around Rome.  Control of the papacy was now the key to significant local material wealth and power in a way that had never been the case before.  It was a fact that did not escape the attention of powerful local Italian families. 

The dark age

By the early tenth century the papacy fell fully under the control of two powerful local families – the Theophylacti and the Cressentii.  These families vied with each other for control of the papacy over most of the next one and a half centuries.  Not only did these families have a significant say in determining who became pope, members of these families sometimes became pope themselves.  It would be remembered as a dark age for the papacy.

The primary focus was on secular power – the power to control the resources of the papal state.  There were, of course, exceptions.  Benedict VIII (1012–1024), a member of the Theophylacti family, took his job quite seriously and actively sought to tackle the pressing religious issues of his day. 

Others…well… were perhaps a little more worldly.

Pope Sergius III (904-911) notoriously took Marozia of the Theophylacti family as his mistress.  This led to accusations that it was she, rather than Sergius, who called the shots.  She would effectively control the papacy from behind the scenes until her deposition by her own son in 932.


Benedict IX, another member of the Theophylacti family, was pope on three separate occasions between 1032 and 1048.  He became pope at the age of 20 with relatively limited religious knowledge, thanks to his family connections.  Benedict lived an entirely dissolute life, so extreme that one of his successors wrote of him:

“He ruled like a captain of banditti, rather than a prelate. Adulteries, homicides perpetrated by his own hand, passed unnoticed, unrevenged; for the patrician of the city, Gregory, was the brother of the pope; and another brother, Peter, an active partisan…” 

Pope Victor III

The excesses of the likes of Marozia and Benedict IX led one historian to label this period of papal history as the ‘Pornocracy’.

However, elsewhere in western Europe the seeds of reform and scholarship planted during the heyday of the Carolingian empire had taken root and were about to bear fruit.


By the eleventh century two major issues faced the church (aside from the papal dependence on the Theophylacti and Cressentii).  The first was the practice of simony – whereby churchmen bought clerical rank with hard cash.  The second was clerical marriage and the fact that a great many priests, bishops, and archbishops were simply not living celibate lives.

The catalyst for change would be a new roman emperor (this time of the holy roman variety) – Henry III.  By 1046 Henry had consolidated his position sufficiently to want to be crowned emperor.  To legitimise his regime, he wanted the pope to do the crowning.  However, at the time the papacy was in a sorry state. 

Three papal candidates were all vying with each other for power.  The infamous Benedict IX was one.  Gregory VI seemed like a decent sort but, since he had bought the papacy from Benedict IX for 1000 pieces of silver, his blatant simony counted against him.  The other wannabe was Sylvester III, about whom little is known but who was almost certainly put up as a candidate by one of the many people who’d grown weary of Benedict IX’s antics.

Henry didn’t like any of them. 

Neither did he like the interfering gerrymandering practised by the local Italian bigshots.  So Henry took a broom to the lot and had his own man, Bruno of Eguisheim, promoted to the top job to become Pope Leo IX.

Problem solver

Although Leo was only pope for six years, he would introduce major reforms.  He actively set about tackling the hot issues of the day – simony and clerical marriage.  He brought several respected scholars and churchmen from around western Europe into the Lateran Palace to help.  Men like Humbert of Moyenmoutier, Hildebrand of Sovana and Peter Damian.  Men who took their religion seriously and had been shaped in the tradition of Latin ecclesiastical scholarship inspired by Charlemagne.  Peter Damian was not only a capable scholar but a hermit and an austere ascetic.  So austere, in fact, that he refused to live in a monastery because he considered the monastic life too luxurious!

Pope Leo himself then went on the road.  He travelled in person to places like Rheims to hold local reform councils, to stamp out corruption and lax practices.  Leo was a pro-active pope of a new kind.  Rather than sitting in Rome and responding reactively only when a problem was brought directly to his attention, Leo was an active problem solver and cage rattler.


It was at this time that the final split with the eastern Church occurred.  There had been disputes between Rome and the eastern Church before.  In the eighth century disputes over iconoclasm the popes had clashed with the views of the eastern emperor and the eastern churches that followed his line.  Other disagreements had followed, some minor and some more significant.

In many ways the key difference between eastern and western Churches was increasingly cultural.  The papacy had become integral with the culture of western Europe, Latin speaking and far closer to the secular powers of the west than to Constantinople.  The eastern Church was culturally Greek and closely bound to the eastern imperial court.

In the end it was a dispute over who had religious authority over southern Italy that led to the final break in 1054.  It ended with an acrimonious mutual excommunication and a permanent schism between the Eastern Orthodox and the Roman Catholic churches.


The papacy still faced a challenge in defining its relationship with secular powers.  It may have broken all links to the eastern emperor but now the influence of western secular powers, especially the Holy Roman Empire, threatened to restrict its independence.  For all Leo’s energetic interventions, the fact was that he had been appointed by the emperor.  Even in the mid-eleventh century, papal power still depended, at least to a degree, on the support of a powerful secular lord.

The process of disconnecting the Holy See from secular control took an important step forward in 1059 when Pope Nicholas II reformed the papal election process.  From then onwards new popes would be elected by a college of cardinals.  Emperors and other secular powers would no longer have any official say in the process.

In 1073 Hildebrand of Sovana, one of the reformers originally brought in by Leo IX became Pope Gregory VII.  He clashed directly with the Holy Roman emperor on the issue of simony.  He also actively attempted to bring the process of appointing bishops and archbishops wholly under the control of the church. 

It was a battle he could not win.  The monarchs of Europe could not afford to surrender all control over senior clerical appointments.  No European king would tolerate a dissenting archbishop (as England’s Henry II would so clearly demonstrate with Thomas Beckett).  However, whilst Gregory ultimately failed, his actions demonstrated a papacy willing to confront kings and emperors and act independently of secular control to a degree previously unheard of.

A balance obviously needed to be struck but the papacy was finally breaking away from simply being the religious lackey of emperors.

Papal authority

The final step in the forging of a fully-fledged medieval papacy of the kind Pope Innocent III represented came not from the actions of any one pope.  Rather it would emerge from ecclesiastical scholarship.

For papal authority to truly govern the whole of the western Church a basic physical problem had to be overcome.  A pope, whether in Rome, or visiting the provinces, can only be in one place at a time.  To extend papal authority across Europe in any real sense, effective delegation was required.  This too began to emerge in the eleventh century as popes began to make increasing use of legates to act as papal representatives when the pope himself could not be present.

The Justinian Codes

In the twelfth century, scholars rediscovered the old Roman law codes of Emperor Justinian.  Copies in Latin began to circulate amongst western scholars, and these provided a template for a solution to the problem of projecting papal authority across such a large geographic area.

Justinian had sought to impose a common standard of laws across his empire.  He had faced the same kind of problem as the popes – he could not be everywhere at once.  To solve this problem, he had created a single coherent set of law codes.  This involved not simply collecting together all the existing law codes but systematically working through them to iron out any inconsistencies and contradictions.  To understand the emperor’s will, all a judge or legate needed to do was to refer to the law codes.

Church scholars now set to work to create a Roman Catholic version of the code of Justinian.  The process of compiling such codes progressed throughout the twelfth century.  In was not simply a case of placing all the decretals, canons and local church council rulings in a single volume of work.  To be useable, it was necessary to group these rulings together in a sensible thematic order.  It was also necessary to tackle any apparent inconsistency or contradiction (for example when the decretals of different popes appeared to reach different conclusions).  After centuries of Church councils, decretals and local councils, there was a lot to go through.

The Harmony of Discordant Canons

The breakthrough in producing a coherent set of codes was a work entitled Concordantia Disconcordantium Canonum (Harmony of Discordant Canons), published in 1140.  Its author, Gratian, organised Church canons and legal rulings under thematic headings and attempted to discuss and resolve any contradictions to establish the correct and up-to-date status of Church law.  It would form a key part of the Corpus Juris Canonici (canon law) used by the Catholic Church throughout the Middle Ages and, indeed, right up until 1917.

From this point on, churchmen and representatives of the Holy See, could increasingly answer doctrinal and legal questions by referring to this Corpus.  The will of the papacy could now be widely distributed in written form across Europe.

And so, by 1215, when the Fourth Lateran Council met, the process was well advanced enough for Pope Innocent III to wield genuine pontifical authority over the western Church. No longer simply a prestigious bishopric, the Holy See was now truly the spiritual heart of western and central Europe.

Portrait of Pope Innocent III
Pope Innocent III

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References & further reading:

The Restoration of Rome.  Peter Heather. Macmillan. 2013.

Wikipedia – history of the papacy


Statue of Saint Peter, holding the keys to heaven – Arnolfo di Cambio, c.1300 (Mattana, Wiki Commons)

Icon from the Mégalo Metéoron Monastery in Greece (JJensen, Wiki Commons)

Map of the Carolingian & Byzantine Empires in 814 (Alphathon, Wiki Commons)

Pope Innocent III – from the Monastery of Subiaco (Wiki Commons)

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