Pope Saint Leo III (795-816)

The pope of a political turning point

Leo III becomes pope at a moment when central Italy has already shifted its centre of gravity. Since the Donation of Pepin and Charlemagne's interventions in Italy, Rome no longer expects its real security from Constantinople, too distant, but from Frankish power. The Catholic Encyclopedia notes that, from his election, Leo sends Charlemagne the keys of Saint Peter's confession and the standard of the city, a sign that he looks to him as protector of the Holy See.^[8]

This gesture is not a spiritual abdication. It reflects a political situation: the pope's Roman adversaries are near at hand, the Byzantines are weak in Italy, the Lombards have been defeated by the Franks, and Charlemagne possesses the military means to protect the Roman Church. Leo III thus inherits Adrian I's line, but in a more dangerous configuration: the Roman aristocracy refuses to let itself be marginalised.

The coronation of 800 is not decoration

The imperial coronation is not a decorative ceremony added to Charlemagne's life. It transforms the language of power in the West. Before Christmas 800, Charles is king of the Franks and Lombards, patrician of the Romans, protector of the Church. After Christmas 800, he bears a Roman imperial title, acclaimed in the basilica of Peter, with the visible intervention of the pope.^[9][10]

But two simplifications must be avoided. Leo does not create Frankish power: Charlemagne already governs an immense whole. Nor does Charlemagne create pontifical authority: Leo acts as bishop of Rome, successor of Peter, in the most symbolic place in Latin Christendom. The gesture succeeds precisely because both realities already exist.

The pope of doctrinal prudence on the Filioque

Leo III combats Adoptionism and confesses the procession of the Holy Spirit according to Western faith. But, in the controversy of the Filioque, he refuses that Rome should alter the received text of the Niceno-Constantinopolitan symbol: what is at stake is the professed and inscribed text — not the singing of the symbol at Mass, which would enter Roman usage only in 1014, under Benedict VIII.^[11] Tradition reports that he had two silver shields placed at Rome bearing the Creed in Greek and Latin without the addition, to defend the received formula.^[12][13]

This position is precious for Catholic ecumenism. Leo does not deny the theological content professed by the West; he distinguishes doctrinal truth from the opportuneness of adding a clause to the common symbol. His decision shows a papacy capable of supporting Frankish orthodoxy while keeping the measure of the universal Church.

Two narratives that do not say exactly the same thing

The life of Leo III is read through two families of sources. Pontifical sources stress the dignity of the pope, his suffering, his restoration and his role in imperial renewal. Frankish sources stress Charlemagne's role as protector, judge of the Roman crisis and beneficiary of the imperial title.^[14]

This tension is not a defect: it is the very subject. The pontificate of Leo III shows how the Roman Church and Carolingian power learn to cooperate without merging. The sources answer one another because the event itself has a double focus: Rome and Aachen, Peter and Charles, altar and empire.

The liturgical testimony

J. F. Romano recalls that four major narrative accounts must be set side by side for the coronation: the Annals of Lorsch, the notice on Leo III in the Liber Pontificalis, the Annales regni Francorum and Einhard.^[15] The study insists on a point often mistranslated: in the Frankish annals, ad missam most probably means at Mass, not merely "to attend Mass".^[16]

The coronation therefore cannot be understood as the handing over of a decoration after a service. It is inserted into the Christmas liturgy, before Saint Peter's confession. For a Catholic reader, this is crucial: the political act is wrapped in a liturgical act, but it does not become a sacrament. It receives a Christian form, without absorbing the spiritual order.

A Roman of Saint Susanna

The Catholic Encyclopedia (Mann, 1910) reports that Leo was Roman, son of Atyuppius and Elizabeth, and that at the time of his election he was cardinal-priest of Saint Susanna, probably also vestiarius, that is, in charge of the pontifical treasury or wardrobe.^[17] The Liber Pontificalis (Duchesne ed., vol. II) for its part names only the father — Asuppius/Atzuppius according to the manuscripts; the mother's first name, Elizabeth, is attested only by the Chronicon Anianense ("natus Rome ex patre Asupio matre Helisabeth", "born at Rome, of a father Asupius and a mother Elizabeth"), a Carolingian chronicle of the early 9th century, from which Mann takes it up — with no support in the pontifical notice.^[18][19][20] Tradition gives no certain date of birth.

These details matter because they place Leo within the Roman personnel of the Lateran. He is not a foreigner installed by the Franks. He is elected from the Roman clergy, immediately after the death of Adrian I, and consecrated the next day or thereabouts, according to the official chronology.^[21]

A swift election to prevent interference

Adrian I dies on 25 December 795; Leo is elected on the 26th and consecrated on the 27th according to the Holy See's list.^[22] New Advent considers it possible that this speed was intended to prevent Frankish intervention in the freedom of the election.^[23]

The nuance matters. Leo needs Charlemagne, but the Romans do not want the Frankish king to manufacture the pope. The Carolingian papacy is therefore not a simple dependency: it seeks an external protector against local factions, while safeguarding the Roman election.

The keys of Saint Peter and the standard of Rome

From his election, Leo informs Charlemagne and sends him two signs: the keys of Saint Peter's confession and the standard of the city.^[24] The first sign points to the apostolic tomb; the second to the Roman city. Together, they say what the pope asks of the king: to protect the memory of Peter and the public order of Rome.

Charlemagne replies with letters of congratulation and with a share of the treasure taken from the Avars.^[25] This money will give Leo considerable room for action for the poor, the churches and monumental restorations.

A hostile aristocracy

Treccani presents Leo as elected by the Roman clergy in opposition to the lay nobility.^[26] New Advent specifies that relatives of Adrian I, moved by jealousy, ambition or desire for revenge, plot to render him unfit for the exercise of his office.^[27]

The political motive is clear: Adrian's old aristocratic network cannot bear the rise of a man of the pontifical clergy who relies on Frankish protection. The quarrel quickly turns brutal, for rendering a pope "unfit" means mutilating him, accusing him, then preventing his government.

The assault of 25 April 799

On 25 April 799, during the procession of the Greater Litanies, Leo makes his way toward the Flaminian Gate. Armed men attack him, throw him to the ground and try to tear out his eyes and tongue.^[28][29][30] The symbolism is transparent: to take from the pope sight and speech is to strike the bodily signs of his government and teaching.

The Liber Pontificalis reports that, through the help of God and the intercession of Saint Peter, Leo recovered sight and speech; the notice sees in it a great miracle accomplished by God through his servant.^[31][32] Thus snatched from an attempt at political disfigurement, Leo returns to government.

"They tried to tear out his tongue and put out his eyes." — Biographical tradition summarised by Horace Mann, Catholic Encyclopedia^[33]

From Rome to Paderborn

After being taken to the monastery of Saint Erasmus on the Caelian Hill, Leo escapes and joins the Frankish representatives, then Charlemagne at Paderborn.^[34][35] The king receives him with honour, but the situation is delicate: the pope's enemies have sent their accusations before the Frankish court.

Leo is therefore not simply "rescued" like a fugitive. He appears politically before the man capable of reinstalling him at Rome. Treccani stresses that Charlemagne has him escorted back by Frankish soldiers, but also orders an inquiry into his conduct, accused by the Roman nobility of adultery and perjury.^[36]

Return to Rome

Charlemagne has Leo escorted to Rome. New Advent reports that the population, Romans and foreigners, welcomes him with joy.^[37] The pope's adversaries are judged by the Frankish envoys, who succeed neither in establishing Leo's guilt nor their own innocence; they are sent as prisoners into Frankish territory.^[38]

This first outcome is not enough. In 800, Charlemagne comes to Rome himself to deal with the dossier. The Roman conflict then becomes the immediate backdrop of the imperial coronation.

Who can judge the pope?

When Charlemagne arrives at Rome, Leo and his accusers are confronted. The assembled bishops declare that they have no right to judge the pope.^[39] The formula does not mean that the pope would be above God or incapable of fault. It means that no ordinary episcopal tribunal can depose the bishop of Rome as a mere subordinate.

The dossier anticipates by far medieval debates on the maxim prima sedes a nemine iudicatur: the first see is judged by no one in the ordinary ecclesiastical order. Leo III does not turn this maxim into a canonical treatise, but the scene of 800 gives it a historical enactment.

A voluntary purgation

To dispel suspicion, Leo nevertheless chooses to take a public oath of innocence. On 23 December 800, he purges himself by oath, holding the Gospel, before Charlemagne, the bishops and the assembly.^[40][41][42]

This gesture is very strong. The pope is not judged by the bishops; nor does he remain silent before the scandal. He pledges his word before God. The solution holds together the authority of the Roman See and the pastoral necessity of removing suspicion.

A spiritual lesson on authority

The oath of Leo III shows that sacred authority does not dispense from public humility. A pastor unjustly accused may have to make a visible act for the peace of the Church. But this act must not be confused with a submission of the Church to a political tribunal.

The true measure is there: Leo purges himself before God; Charlemagne guarantees order; the bishops recognise that they cannot judge the Roman See; two days later, the pope crowns the one who protected him.

The place: the old Saint Peter's Basilica

On 25 December 800, Charlemagne is at Christmas Mass in the old Saint Peter's Basilica. The Annales regni Francorum place the gesture before the confession of blessed Peter, at the moment when the king rises from prayer.^[43] Romano stresses that this liturgical detail is part of the force of the event: the king kneels before the apostle, then receives the crown from the pope.^[44]

The place forbids a purely political reading. The ceremony takes place neither at the Lateran palace, nor in a courtroom, nor at Aachen. It takes place on Peter's tomb, in the liturgy of the mystery of the Incarnation.

The crown and the acclamation

The Frankish annals report the scene with famous concision: Leo imposes the crown; the Roman people acclaim Charles as Augustus, crowned by God, great and peace-bringing emperor of the Romans; the title of patrician is replaced by that of emperor and Augustus.^[45][46]

"After he had received this praise, he was adored by the pontiff in the manner of the ancient princes, and, abandoning the name of patrician, he was called emperor and Augustus." — Annales regni Francorum, entry for 801 (event of 25 December 800)^[47]

The sequence is decisive: a crown placed by the pope, an acclamation borne by the Roman people, a homage rendered to the newly crowned, a new title replacing that of patrician. It is not only a blessing: it is an entry into imperial grammar, where each public gesture states the change of rank.

Was Charlemagne taken by surprise?

Einhard asserts that Charlemagne at first had such an aversion to imperial titles that he reportedly said he would not have entered the church that day had he known the pontiff's design.^[48]

"He declared that he would not have entered the church that day, despite the solemnity of the feast, if he could have known the pontiff's design." — Einhard, Life of Charlemagne, ch. 28^[49]

This sentence must not be read naively. Einhard writes after the fact; Romano judges the literal reading of a Charlemagne made emperor against his will to be questionable.^[50] The same Romano notes that Einhard takes care to distance Charlemagne from the Byzantine emperors, presented as indignant at his new title.^[51] To see in this a calculated precaution of the Carolingian milieu toward Constantinople — not giving the impression of a deliberate usurpation of the Roman title — nevertheless remains an interpretation attributed to modern historians, not an intention established by these pages: this point stays open. Perhaps Charles disliked the precise form of the gesture, but the idea of an imperial dignity was in the air.

A restoration of the empire in the West

New Advent sums up the theoretical meaning of the gesture: the Empire is revived in the West, and the new emperor receives as his first task to protect the Roman Church and Christendom.^[52] One must be precise: this is not the administrative resurrection of the ancient Roman Empire. It is a new Christian, Latin, Carolingian imperial dignity, centred on the protection of Rome.

What follows will show the ambiguity. From the pontifical point of view, Leo gives the crown. From the Frankish point of view, Charlemagne already possesses the power that makes the title credible. From the Byzantine point of view, a Western competitor appears. From the ecclesial point of view, the emperor must serve the defence of the Church, not take its place.

The protector becomes emperor

After Christmas 800, the bond between Leo and Charlemagne changes form. The protecting king becomes emperor; the pope who asked for protection becomes the one who crowned him. The coins of Leo III bear the name of the Frankish emperor together with that of the pope, a sign, according to New Advent, that the emperor is protector of the Church and suzerain of the city.^[53]

This reality may unsettle too romantic a reading. Leo is not an isolated sovereign, free of all power relations. He acts in an order where Frankish protection weighs heavily. Treccani goes so far as to say that he always remained subject to Charlemagne's decisions.^[54] The formula is severe, but it recalls a truth: the gesture of 800 does not remove Roman political dependence.

The idea of a marriage with Irene

New Advent reports that Leo sought to favour the plan of a marriage between Charlemagne and the Byzantine empress Irene, in order to unite East and West under an effective common government; the deposition of Irene in October 802 made the plan impossible.^[55][56] (New Advent gives 801, an erroneous date: Irene was deposed in October 802 in favour of Nicephorus I.)

The information shows that the coronation is not immediately conceived as a definitive rupture with Constantinople. A dynastic-union solution still seems conceivable. But history takes another path: the two empires coexist, partially recognise each other, dispute the Roman name and prepare new tensions between East and West.

English affairs

Leo and Charlemagne also intervene in the affairs of the English Church. New Advent mentions the restoration of Eardwulf of Northumbria, the regulation of a conflict between Archbishops Eanbald of York and Wulfred of Canterbury, the excommunication of Eadberht Praen who had seized the throne of Kent, and the withdrawal of the pallium of Lichfield — the pallium, the white woollen band the pope confers on archbishops as a sign of communion with Rome and of metropolitan jurisdiction — in favour of restoring Canterbury's jurisdiction.^[57]

These dossiers recall that the Carolingian papacy is not limited to Rome and the empire. It also intervenes in the ecclesial geography of the Latin West, often in link with Frankish power.

Spanish Adoptionism

Leo III and Charlemagne act together against Adoptionism, a doctrine associated notably with Elipandus of Toledo and Felix of Urgell, which presents Christ, in his humanity, as the adopted Son of God. Treccani speaks of a "definitive condemnation" of Adoptionism at the "sinodo del 799".^[58] The articulation must be specified and the Roman date corrected: the doctrine had already been condemned at Regensburg (792) then solemnly at Frankfurt (794); it is the Roman council of 798, under Leo III, which confirms — and does not inaugurate — this condemnation^[59]; then, in spring 799, Felix of Urgell abjures at Aachen before Alcuin. New Advent confirms that pope and emperor fight together against this heresy come from Spain.^[60]

The question is not secondary. To say that Christ as man would be an adopted son risks dividing the one person of the incarnate Word. Catholic faith confesses one Son, true God and true man: the humanity of Christ is not that of an external man adopted by God; it is the humanity personally assumed by the eternal Son.

The Filioque: believing the doctrine, keeping the symbol

The Filioque dossier is more subtle. The West confesses that the Holy Spirit proceeds from the Father and the Son. Charlemagne and his theologians wish to give this confession a more general liturgical expression in the Creed. Leo, for his part, upholds the faith, but shows himself reluctant to alter the received text of the symbol.^[61][62]

The tradition of the silver shields sums up his position. Leo is said to have had the Creed engraved at Rome in Greek and Latin, without the addition, as a witness to orthodox faith and to the received form.^[63][64] This is therefore not a pope "anti-Filioque" in the doctrinal sense. He is a pope who refuses to treat the formula of the symbol as a text easily modifiable under political pressure.

"Hic vero pro amore et cautela ortodoxe fidei fecit [...] scutos ex argento II, scriptos utrosque simbolum, unum quidem litteris grecis et alium latinis" ("It is through love and for the safeguarding of orthodox faith that in this same place [Saint Peter's Basilica] he had two silver shields made, each inscribed with the symbol, one in Greek letters and the other in Latin") — Liber Pontificalis, Life of Leo III, ch. LXXXIV^[65][66]

Besides this testimony of the Liber Pontificalis, there exists a Latin account of the dialogue of 810 between the Frankish envoys and Leo III, transmitted by Smaragdus, whose redactor himself acknowledges the limits of his memory^[67]; by contrast, no precise French formula lent to Leo on this point corresponds word for word to an authenticated Latin sentence. His position is therefore summed up in paraphrase: holding the Western doctrine of the procession to be true, without touching the received text of the symbol.

A Catholic prudence still relevant

The distinction of Leo III is a model of prudence. There are truths that must be professed; there are also common liturgical forms that must be handled with gravity. Catholic theology is not reduced to maximising exact formulations without regard for received unity.

This point is particularly useful for reading the later great schism. The history of the Filioque does not begin in 1054. Leo III shows that in 809-810, Rome already knows the doctrine, substantially supports it, but still refuses to impose the addition on the symbol professed and inscribed at Rome — without prejudging the singing of the symbol at Mass, which would enter there only in 1014.^[68]

The Avar treasures and service of the poor

Charlemagne gives Leo a large share of the treasure taken from the Avars. New Advent explains that this wealth enabled the pope to be a great benefactor of the churches and charitable institutions of Rome.^[69]

The detail matters spiritually. Leo does not merely turn Frankish protection into prestige. He converts it into visible works: relief of the poor, restoration of basilicas, embellishment of holy places, consolidation of the Christian city.

Restoring the churches

New Advent mentions the renovations of churches at Rome and even at Ravenna, as well as the use of mosaic, notably in his titular church of Saint Susanna.^[70] The most famous monumental memory of the pontificate nevertheless remains the mosaic of the Lateran triclinium, known through its reconstruction, where Saint Peter hands the pallium to Leo and the standard to Charlemagne.

This image says in visual theology what the texts say in politics: Peter remains the apostolic source; the pope receives his pastoral mission; the Frankish king receives a charge of protection. The Christian order is not only a human alliance, but a mission received under the gaze of the apostle.

A Carolingian Rome, but a Roman one

Leo III brings Rome into the Carolingian orbit without dissolving it into the empire. Restorations, mosaics, gifts and inscriptions display a new language: the Franks protect, finance, influence; but the symbolic centre remains the city of Peter.

This point avoids a frequent error: imagining that the papacy simply becomes an imperial chapel. Leo must deal with Charlemagne, but he does not cease to be bishop of Rome. Basilica, confession of Peter, Lateran, relics and the poor keep the pontificate's own logic.

After Charlemagne

Charlemagne dies on 28 January 814. The protector's disappearance brings Roman tensions back to the surface. Treccani reports that hatreds and conspiracies break out again at Rome, and that Leo answers with reprisals so harsh that Emperor Louis the Pious wants an inquiry led by Bernard, king of Italy.^[71] The dossier nevertheless runs its course in 815: Bernard, fallen ill at Rome, conveys what he has observed through Count Gerold, then the pope's envoys — Bishop John of Silva Candida, the nomenclator Theodore and Duke Sergius — answer point by point the grievances brought against their master, to the emperor's satisfaction.^[72]

This darker ending recalls that the pontificate is not only the glory of Christmas 800. Leo remains caught in a violent city, where pontifical power is built amid factions, aristocratic memories and military dependence.

Death and canonisation

Leo III dies on 12 June 816 and, according to the Catholic Encyclopedia (Mann, 1910), he was buried at Saint Peter's, where his relics are said to lie with those of Leo I, Leo II and Leo IV.^[73] His feast is celebrated on 12 June — Treccani's current notice is entitled "Leone III papa, santo" and indicates "Festa, 12 giugno"^[74]; his canonisation is dated 1673 according to the Mann notice.^[75]

The 1673 act has not been reviewed here. Leo III is venerated as a pope whose life unites suffering, government, political courage, doctrinal defence and service of holy places.

A holiness of government

The holiness of Leo III is not that of a hermit nor that of a clearly attested martyr. It is a holiness of government in a hard world: holding Rome, surviving violence, seeking a protector without selling Peter's charge, making an imperial gesture without confusing altar and throne, defending the Creed without turning doctrinal precision into liturgical brutality.

His life teaches that Catholic authority often unfolds in imperfect situations. Leo III did not choose a peaceful age. He governed when the choice lay between Roman isolation, aristocratic pressure, waning Byzantine dependence and the Frankish alliance. His merit was to make of this alliance an instrument for the protection of the Church, not a disappearance of the Church into the empire.

• The Coronation of Charlemagne — the specialised article on Christmas 800.
• The Carolingian Reform — the religious and cultural reform carried by the Frankish world.
• Council of Nicaea II — the context of the Byzantine East and of images.
• The Quarrel over Images — major crisis between Byzantine emperors, monks and papacy.
• The Photian Schism — a later stage of Rome-Constantinople tensions.
• The Great Eastern Schism — the long backdrop of the Filioque dossier and Roman primacy.
• The Pontifical States — the rise of the popes' temporal power.