The Libri Carolini, commissioned by Charlemagne and authored primarily by Theodulf of Orléans, represents the Carolingian response to the Second Council of Nicaea's (787) endorsement of icon veneration. This comprehensive theological treatise articulates a nuanced middle position—accepting images for didactic and decorative purposes while rejecting their veneration as potentially idolatrous. Though suppressed in its own time to avoid conflict with the papacy, the work resurfaced during the Reformation and remains a crucial witness to Carolingian theological thought and the intellectual achievements of Charlemagne's court.

Introduction

First page of a 9th-century manuscript of the Libri Carolini, showing the preface written in Charlemagne’s name. This Carolingian treatise was composed to rebut the Second Council of Nicaea (787) on the issue of sacred images.
The Libri Carolini (Latin for “Charles’ Books”), also known as the Opus Caroli regis contra synodum (“The work of King Charles against the [Greek] Synod”), is a monumental theological treatise from the late 8th century. Commissioned by Charlemagne in the mid-790s, it was written in response to the Second Council of Nicaea (787) – the Eastern council that had restored the veneration of icons in the Byzantine Empire (Libri Carolini - Wikipedia). The Carolingian court viewed the Nicene decrees on images with suspicion and crafted the Libri Carolini to refute what they perceived as the excesses of image-veneration. Long unknown in the Middle Ages, this work resurfaced only in the 16th century, when it stirred intense interest amid Reformation debates over religious images (Libri Carolini - Wikipedia). In what follows, we will examine the historical context that gave rise to the Libri Carolini, summarize its theological arguments against the veneration of images, discuss its authorship and place in the Carolingian Renaissance, and evaluate its impact and reception from the 8th century through the Reformation. Comparisons with other contemporary theological texts will help illuminate the unique rhetorical and doctrinal strategies employed in this treatise.

Historical Context: Carolingians, Icons, and the 787 Council

In the 8th century, Christendom was divided over the question of religious images. The Byzantine East had experienced decades of Iconoclasm (image-breaking), as emperors and certain bishops opposed the use of icons in Christian worship. This controversy climaxed at the Second Council of Nicaea (787), convened by Empress Irene and her young son Constantine VI. Nicaea II – regarded by the Eastern Church as the Seventh Ecumenical Council – condemned iconoclasm and affirmed the veneration (proskynesis) of icons, distinguishing such veneration from the worship (latreia) due to God alone ( Nicene and Post-Nicene Fathers, Series II, Vol. XIV ). The Pope in Rome (Hadrian I) supported the council’s decrees, thus aligning the papacy with the pro-image stance of the Eastern iconophiles.

Meanwhile, in the Carolingian Empire under Charlemagne, news of Nicaea II was met with skepticism. The Frankish Church had not been represented at the council, and when Charlemagne obtained a Latin translation of its acts, the text was deeply flawed. The Latin version of the Nicene acts was “a monument of inadequate translation,” so garbled that it outraged Charlemagne’s theologians ( L’Europe héritière de l’Espagne wisigothique - Theodulf of Orleans: a Visigoth at Charlemagne’s Court - Casa de Velázquez ). Based on this faulty report, the Franks believed that the Eastern bishops had sanctioned nothing less than “adoration” of images, putting icons on par with the Holy Trinity ( Nicene and Post-Nicene Fathers, Series II, Vol. XIV ) ( Nicene and Post-Nicene Fathers, Series II, Vol. XIV ). Such a notion smacked of idolatry to the Franks.

Charlemagne’s court reacted swiftly. In 792, the first Carolingian critiques of Nicaea II were drafted (the so-called Capitulare adversus synodum) and sent to Pope Hadrian I (Libri Carolini - Wikipedia). Hadrian, who had endorsed the council, replied with a defense of the Nicene position. Unpersuaded, Charlemagne ordered a more comprehensive rebuttal to both Nicaea II and Hadrian’s arguments. The result was the Libri Carolini, completed by the mid-790s (Libri Carolini - Wikipedia) (Libri Carolini - Wikipedia). Though written in Charlemagne’s name and intended as an official Frankish statement, the work was never promulgated publicly. By 794, Charlemagne convened the Council of Frankfurt, where Frankish bishops – in the presence of papal legates – formally rejected the authority of Nicaea II and its endorsement of image-veneration ( Nicene and Post-Nicene Fathers, Series II, Vol. XIV ). However, Pope Hadrian refused to denounce Nicaea II, creating a delicate impasse between Frankish and papal policy ( L’Europe héritière de l’Espagne wisigothique - Theodulf of Orleans: a Visigoth at Charlemagne’s Court - Casa de Velázquez ). Realizing that open conflict with Rome would be fruitless, Charlemagne shelved the Libri Carolini before it was ever sent to the Pope (Libri Carolini - Wikipedia). The treatise languished in obscurity, surviving in a few manuscripts but largely ignored as the Western Church gradually came to accept the Eastern council’s views on images in the centuries that followed ( L’Europe héritière de l’Espagne wisigothique - Theodulf of Orleans: a Visigoth at Charlemagne’s Court - Casa de Velázquez ).

Politically, the Libri Carolini must be understood against the backdrop of Charlemagne’s imperial ambitions and the Franks’ self-image as defenders of orthodox Christianity. The text does not merely rebut theological points; it pointedly attacks the conveners of Nicaea II – Empress Irene and her son – as heretical and unworthy rulers (). In a polemic of proto-imperial tone, it even likens the Byzantine Empire’s spiritual state to that of “pagan Babylon,” while implying that the Franks are God’s new chosen people (“nos, qui spiritualis Israel sumus” – “we, who are the spiritual Israel”) () (). Such language reflects a Carolingian view that their kingdom was the true champion of Christian orthodoxy, in contrast to a misguided Greek East. It is no coincidence that within a decade of writing this treatise, Charlemagne would be crowned “Emperor” in Rome (800): the Libri Carolini can be seen as laying ideological groundwork for a western empire rivaling Byzantium, with the Franks portrayed as the guardians of pure faith ().

The Carolingian Critique of Images: Theology of the Libri Carolini

At the heart of the Libri Carolini is a nuanced theological position on sacred images – a via media (middle path) distinct from both the Byzantine iconophiles and the iconoclasts. The Carolingian theologians accepted the presence of images in churches but rejected their veneration. In their view, religious images have value as decorative and didactic objects: they beautify churches, illustrate biblical history, and educate the faithful, especially the illiterate, about sacred truths (Libri Carolini - Wikipedia). However, images are not to be given any sort of adoration, reverence, or ritual honor. The Libri Carolini explicitly states that it is “foolish” to burn incense or light candles before images, as if they were holy altars, and equally foolish to pray to them or attribute miraculous powers to them (Libri Carolini - Wikipedia) (Libri Carolini - Wikipedia). On the other hand, the text also condemns the opposite extreme: it is “quite wrong,” the Frankish authors say, to throw images out of churches or to destroy them (Libri Carolini - Wikipedia). In sum, images occupy a legitimate but strictly limited place: “for purposes of instruction, and in memory of past events” – not as objects of cultic veneration (Libri Carolini - Wikipedia). This stance was presented as the traditional, truly orthodox practice of the Church, avoiding both the iconoclasts’ total rejection and the Greeks’ (perceived) excess of honor towards images (Traité sur les images, dit Libri carolini - BnF Essentiels) (Traité sur les images, dit Libri carolini - BnF Essentiels).

A major portion of the Libri Carolini is devoted to a point-by-point refutation of the Second Council of Nicaea (787) and its theological rationale for icon-veneration. The Carolingian authors were aware that Nicaea II had attempted to carefully distinguish the veneration (Greek proskynesis, Latin veneratio) given to icons from the adoration (latreia, Latin adoratio) due to God alone (Libri Carolini - Wikipedia). Indeed, the Libri Carolini even paraphrases the council’s claim: “We do not adore images as God nor do we pay them divine worship.” (Libri Carolini - Wikipedia) Yet the Franks were not mollified by this distinction. They argued that no scriptural or patristic warrant exists for requiring any kind of reverence toward images. Even a lesser “honor” (honorarium veneratio) paid to images was, in their view, unwarranted and dangerous. The authors point out that generations of early saints, martyrs, and monks had not used or venerated images, so to elevate images now was to innovate beyond apostolic tradition (Libri Carolini - Wikipedia) (Libri Carolini - Wikipedia). The Libri Carolini bristles at the idea that any Christian could be anathematized (as Nicaea II had decreed) for refusing to honor images – asserting that such a requirement has no basis in the core of the faith (Libri Carolini - Wikipedia). Faith in Christ, they insist, cannot be equated with reverence for icons (Libri Carolini - Wikipedia).

Throughout the treatise, the Carolingians buttress their arguments with extensive citations of Church Fathers and ecclesiastical authorities, demonstrating impressive scholarly range. Notably, they invoke Pope Gregory the Great (Gregory I) – often considered a key authority on the use of images – to bolster their moderate position. Gregory, writing a century earlier to a bishop who had destroyed images, famously taught that images in church are “placed not to be adored, but to instruct the minds of the ignorant.” The Libri Carolini seizes on this dictum (Libri Carolini - Wikipedia), accusing Pope Hadrian I (who defended Nicaea II) of betraying the true heritage of the Roman Church by endorsing the council’s pro-icon stance (Libri Carolini - Wikipedia). In other words, the Frankish theologians tried to show that their rejection of image-veneration was grounded in old and authoritative Western tradition, whereas the Eastern iconophiles – and the Pope following them – had gone beyond tradition into error.

The Carolingians also challenge some of the specific theological justifications that the iconodules had offered. For example, Eastern defenders of icons (like St. John of Damascus, whose writings informed Nicaea II) argued that because Christ, the invisible God, became visible in the Incarnation, it is legitimate to depict Him in images; they also held that honor shown to an image passes to its prototype (the saint or divine figure depicted). The Libri Carolini counters such reasoning by emphasizing that no image created by human hands can mediate grace or possess inherent sanctity. The Frankish authors ridicule the notion (found in some Nicene documents) that miracle-working power could be ascribed to icons (Libri Carolini - Wikipedia) (Libri Carolini - Wikipedia). They maintain a clear ontological divide between the material and the divine: images are lifeless artifacts – useful for reminding believers of holy things, but unable to channel supernatural power or prayer. Prayer and worship must be directed to God alone, not mediated through painted wood or stone (Libri Carolini - Wikipedia) (Libri Carolini - Wikipedia).

It is important to note that modern scholarship has revised the older view that the Libri Carolini simply misunderstood the Greeks due to a bad translation. Early critics accused the Franks of ignorantia – failing to grasp that the Greeks distinguished veneration from worship. While it is true the Latin Acts Charlemagne received were poorly translated and did blur some nuances ( L’Europe héritière de l’Espagne wisigothique - Theodulf of Orleans: a Visigoth at Charlemagne’s Court - Casa de Velázquez ) ( L’Europe héritière de l’Espagne wisigothique - Theodulf of Orleans: a Visigoth at Charlemagne’s Court - Casa de Velázquez ), the Carolingian theologians actually show awareness of the intended distinction (Libri Carolini - Wikipedia) (Libri Carolini - Wikipedia). Recent studies conclude that the Franks consciously rejected the Byzantine position not out of confusion, but out of conviction (Libri Carolini - Wikipedia) (). In their judgment, even a subtler “veneration” of images was a step too far, shading into superstition (superstitio) or even idolatry. Thus, the Libri Carolini articulates a consistent theology: images are useful, even important, as adornments and teaching tools, but they must remain essentially “dead” signs – never objects of prayer, devotion, or trust (Libri Carolini - Wikipedia).

Authorship and the Carolingian Renaissance

Although the treatise opens with a preface in Charlemagne’s voice, modern scholars concur that Charlemagne did not personally write the Libri Carolini (Libri Carolini - Wikipedia). The work was a product of his court of scholars – an embodiment of the Carolingian Renaissance intellectual enterprise – and was issued under the king’s authority. Today, the primary author is believed to be Theodulf of Orléans, a prominent theologian and Bishop of Orléans (c. 750–821) (Libri Carolini - Wikipedia). Theodulf was a Visigothic Spaniard by birth, one of the learned men whom Charlemagne gathered to his court. He was renowned as a poet, biblical scholar, and reformer, and he played a key role in many of Charlemagne’s ecclesiastical initiatives. Anne Freeman’s seminal studies (1950s–1980s) demonstrated that the linguistic and liturgical peculiarities in the Libri Carolini (such as Visigothic Latin spellings and unique quotations from the Spanish liturgy) point unmistakably to Theodulf’s hand ( L’Europe héritière de l’Espagne wisigothique - Theodulf of Orleans: a Visigoth at Charlemagne’s Court - Casa de Velázquez ) ( L’Europe héritière de l’Espagne wisigothique - Theodulf of Orleans: a Visigoth at Charlemagne’s Court - Casa de Velázquez ). Indeed, as one scholar notes, “the treatise is indeed Theodulf’s work”, containing telltale traces of his style and background on every page ( L’Europe héritière de l’Espagne wisigothique - Theodulf of Orleans: a Visigoth at Charlemagne’s Court - Casa de Velázquez ). Theodulf’s mastery of Latin rhetoric and logic is evident in the text’s tightly argued structure: he uses classical rhetorical techniques and syllogistic reasoning to build his case, while peppering the discussion with copious biblical and patristic references ( L’Europe héritière de l’Espagne wisigothique - Theodulf of Orleans: a Visigoth at Charlemagne’s Court - Casa de Velázquez ) ( L’Europe héritière de l’Espagne wisigothique - Theodulf of Orleans: a Visigoth at Charlemagne’s Court - Casa de Velázquez ). This erudition reflects the spirit of the Carolingian Renaissance – a revival of learning in which Charlemagne’s court sought to restore and emulate the classical and patristic heritage of Christianity.

It appears that Theodulf composed the Libri Carolini around 790–792, likely making it the first major project he undertook for Charlemagne ( L’Europe héritière de l’Espagne wisigothique - Theodulf of Orleans: a Visigoth at Charlemagne’s Court - Casa de Velázquez ). This timing aligns with Theodulf’s arrival at the royal court (perhaps by 789) and the court’s reception of the Acts of Nicaea II. We know that Charlemagne’s circle initially considered issuing a royal capitulary or manifesto against the “Greek” errors on images ( L’Europe héritière de l’Espagne wisigothique - Theodulf of Orleans: a Visigoth at Charlemagne’s Court - Casa de Velázquez ). Theodulf, drawing inspiration from Visigothic precedents in his native Spain (such as King Reccared’s proclamations against heresy), structured much of the treatise as a king’s proclamation of orthodoxy ( L’Europe héritière de l’Espagne wisigothique - Theodulf of Orleans: a Visigoth at Charlemagne’s Court - Casa de Velázquez ). However, the plan evolved: as the drafting progressed – and perhaps as Alcuin of York and others gave input – a concluding section was added suggesting that a synod of bishops could ultimately settle the matter ( L’Europe héritière de l’Espagne wisigothique - Theodulf of Orleans: a Visigoth at Charlemagne’s Court - Casa de Velázquez ). This change foreshadowed the Council of Frankfurt in 794. In effect, the Libri Carolini was both an exercise in imperial theology and a contribution to conciliar debate.

Charlemagne’s own influence on the content should not be understated, even if he was not the author per se. The views expressed closely reflect Charlemagne’s thinking on the matter (Libri Carolini - Wikipedia). By all accounts, Charlemagne was deeply troubled by the idea that art could rival scripture or theology in conveying truth – he “did not accept that art had any advantages over books” as tools for teaching the faith (Libri Carolini - Wikipedia). This skepticism toward visual theology pervades the Libri Carolini. In commissioning the work, Charlemagne provided patronage and impetus for a comprehensive statement of the Frankish ecclesiastical stance, one that would assert his realm’s leadership in defining orthodoxy. The treatise’s elaborate arguments and extensive learning also demonstrate the resources available in Charlemagne’s scholarly circle. The Carolingian Renaissance created the conditions for such a text: access to libraries of Patristic writings (Theodulf brought many books from Spain ( L’Europe héritière de l’Espagne wisigothique - Theodulf of Orleans: a Visigoth at Charlemagne’s Court - Casa de Velázquez )), a revival of theological inquiry, and an environment where classical learning and Christian doctrine were jointly pursued. The Libri Carolini is thus a showcase of Carolingian Renaissance scholarship – “the most ambitious treatise of the age”, as one historian describes it ( L’Europe héritière de l’Espagne wisigothique - Theodulf of Orleans: a Visigoth at Charlemagne’s Court - Casa de Velázquez ) ( L’Europe héritière de l’Espagne wisigothique - Theodulf of Orleans: a Visigoth at Charlemagne’s Court - Casa de Velázquez ), serving both the court’s political agenda and its intellectual curiosity.

Impact and Reception: From Carolingian Obscurity to Reformation Rediscovery

The immediate impact of the Libri Carolini during Charlemagne’s reign was limited by realpolitik. As noted, the treatise was never formally published or disseminated in its time, likely to avoid an open breach with the papacy (Libri Carolini - Wikipedia). Instead, its ideas influenced the Council of Frankfurt (794), where Charlemagne and his bishops echoed its conclusions by condemning the supposed “adoration” of images and denying Nicaea II’s ecumenical authority ( Nicene and Post-Nicene Fathers, Series II, Vol. XIV ). The council’s canon on images (though brief) essentially upheld the Libri Carolini’s position: that no Christian should be compelled to venerate images, and that the Frankish Church rejected the Eastern decree as unauthorized innovation ( Nicene and Post-Nicene Fathers, Series II, Vol. XIV ) ( Nicene and Post-Nicene Fathers, Series II, Vol. XIV ). However, beyond Frankfurt, there was little attempt to promote the Carolingian view further. When Charlemagne died in 814, the controversy over icons was subsiding; the Eastern Empire itself fell back into iconoclasm in 815, delaying a permanent resolution until 843 (the Triumph of Orthodoxy). In the West, the Papacy eventually reaffirmed the legitimacy of Nicaea II. Thus, the Frankish anti-icon decrees never became part of general Church law.

For centuries thereafter, the Libri Carolini remained virtually forgotten. Only a few copies survived in monastic libraries. Tellingly, one copy was made for Archbishop Hincmar of Reims in the 9th century ( L’Europe héritière de l’Espagne wisigothique - Theodulf of Orleans: a Visigoth at Charlemagne’s Court - Casa de Velázquez ) – indicating that at least some later Carolingian churchmen studied the work. Hincmar, a powerful 9th-century figure, perhaps saw value in the treatise’s theological analysis, but even he did not manage to bring its ideas into the mainstream. No medieval council or major theologian openly championed the Libri Carolini’s view after the 9th century. In fact, as the cult of images and relics grew in medieval piety, the Carolingian position might have appeared anachronistically austere. By the High Middle Ages, the Western Church fully embraced the veneration of images in line with the Byzantine practice, and the Libri Carolini’s mild iconoclasm (or at least icono-skepticism) was out of step. Church writers who did address images – for instance, St. Thomas Aquinas in the 13th century – took for granted the correctness of Nicaea II, a council which by then was recognized in the West as the Seventh Ecumenical Council. Meanwhile, the authorship of the Libri Carolini remained obscure; medieval catalogues sometimes still attributed it to Charlemagne himself or simply kept it anonymous.

A dramatic turn in the Libri Carolini’s fortune came in the Protestant Reformation. The text was rediscovered and published in 1549 by the French scholar Jean du Tillet (Libri Carolini - Wikipedia). This occurred in a context where Reformation theologians were fiercely criticizing the Catholic Church’s use of images. The resurfacing of a Carolingian-era critique of image-veneration caused, as one account notes, “excitement and confusion” (Libri Carolini - Infogalactic: the planetary knowledge core). Protestants were delighted to find that a revered Christian ruler (Charlemagne) and his theologians had once denounced what the medieval Catholic Church later practiced. The Libri Carolini was quickly appropriated in the polemics of the time: the reformer John Calvin, for example, cited it approvingly in his Institutes of the Christian Religion (Book I, chapter 11) as evidence that even early medieval authorities condemned the veneration of images (Libri Carolini - Wikipedia). Calvin leveraged the Carolingian arguments to bolster the Reformed position that images should not be honored in worship (Libri Carolini - Wikipedia). Other Protestant writers similarly held up the treatise as a witness against “popish” idolatry.

The Catholic response to this embarrassing Carolingian testimony was defensive. Some countered that the Carolingians had been mistaken or that the Libri Carolini was never an authoritative statement of the Church. Ultimately, the Catholic Church placed the Libri Carolini on the Index of Forbidden Books, possibly because of its iconoclastic tenor and its implication of imperial interference in doctrine (Libri Carolini - Wikipedia). (It remained on the Index until 1900 (Libri Carolini - Wikipedia).) Ironically, a treatise that had lain dormant for 800 years suddenly became a hot item in 16th-century confessional debates. Its influence during the Reformation was significant insofar as it gave Protestant apologists historical ammunition and forced Catholic scholars to reckon with an inconvenient chapter of their own past. However, beyond the polemical sphere, the Libri Carolini did not alter church policy – the Catholic Church at the Council of Trent (1560s) reaffirmed the proper use and veneration of images, effectively siding with Nicaea II and not the Carolingians.

In modern times, the Libri Carolini has attracted considerable scholarly attention as a window into Carolingian thought and as “the fullest statement of the Western attitude to representational art” from the early Middle Ages (Libri Carolini - Wikipedia). A critical edition of the Latin text, edited by Ann Freeman and Paul Meyvaert, was published in 1998 (Libri Carolini - Wikipedia), finally giving the work a reliable text and confirming Theodulf’s authorship. Historians and theologians now study the Libri Carolini not as a doctrinal authority (it holds no normative weight in any church) but as a fascinating intellectual artifact: it reveals the complexities of early medieval theology, the interplay of politics and religion under Charlemagne, and the divergent development of Eastern and Western Christian practices.

Comparison and Evaluation: The Libri Carolini in Context

To fully appreciate the Libri Carolini, it is helpful to compare it with other theological texts and positions of its era, and to critically assess its strategies. In the panorama of the 8th–9th centuries, this work stands almost alone in the Latin West as a sustained theological critique of icon-veneration. The Byzantine world had many treatises on this topic – most famously, St. John of Damascus’s On the Divine Images (c. 730s) defending icons, and the iconoclastic council of 754’s decree condemning them – but the Carolingians crafted a response independent of both extremes. In essence, the Libri Carolini formulated a third position. It agreed with the iconoclasts that worshiping or overly reverencing images was wrong (the Franks even used the label “superstitious adoration” for what they thought the Greeks did ( L’Europe héritière de l’Espagne wisigothique - Theodulf of Orleans: a Visigoth at Charlemagne’s Court - Casa de Velázquez ) ( L’Europe héritière de l’Espagne wisigothique - Theodulf of Orleans: a Visigoth at Charlemagne’s Court - Casa de Velázquez )). Yet it vehemently disagreed with Byzantine iconoclasts’ complete ban on images, calling that approach impious and ignorant of how images can serve the Church (Libri Carolini - Wikipedia). The result is a nuanced stance that echoes earlier Western sentiments (like Pope Gregory’s) and anticipates later debates (the Protestant refusal of images) – truly a via media. In comparison, Pope Hadrian I’s defense of Nicaea II (his letters to Charlemagne around 793) took the opposite tack: Hadrian insisted the council did not teach idol-worship and tried to reassure the Franks that only relative honor was being given to icons, citing many of the same Fathers but reaching a pro-image conclusion (Libri Carolini - Wikipedia) (Libri Carolini - Wikipedia). Theodulf and his colleagues found Hadrian’s arguments unconvincing, illustrating the growing independence of Frankish theological reasoning even vis-à-vis the papacy.

Rhetorically, the Libri Carolini is a forceful piece of work. It employs a variety of strategies to make its case persuasive. One notable approach is the portrayal of the opponents in stark terms: the text bristles with language condemning the Byzantines’ alleged hubris. It speaks of the Eastern council acting “recklessly and arrogantly” in decreeing the adoration of images (Libri Carolini - Wikipedia) (Libri Carolini - Wikipedia). It labels the image-venerating practice as “blasphemy” and “idolatry,” and casts the Byzantine Empress and emperor as modern Nebuchadnezzars leading a new Babylon () (). Such harsh characterization aims to delegitimize the proponents of icon-veneration by associating them with heresy and even paganism. This fiery tone is similar to other Carolingian polemics of the era – for example, the way Carolingian theologians condemned the Adoptionist heresy in Spain with strong epithets. It reflects a wider trend in early medieval controversial literature: opponents are not merely in error, but portrayed as proud violators of divine truth. By contrast, John of Damascus’s treatises (and the Acts of Nicaea II) took a more irenic, explanatory tone to win over doubters on icons, carefully drawing theological distinctions. The Carolingians instead marshaled ridicule and scorn as weapons – calling the practice of venerating paint and wood absurd, and sarcastically asking whether images were baptized or received the Holy Spirit such that they deserve honor (Libri Carolini - Wikipedia) (Libri Carolini - Wikipedia). This kind of pointed questioning reveals the logical training of Theodulf: he reduces the pro-icon arguments to what he sees as absurd conclusions, a technique borrowed from classical rhetoric.

Another strategy is the heavy use of authoritative sources. The Libri Carolini cites Scripture extensively, as well as the Church Fathers (Augustine, Jerome, Gregory the Great, etc.) and conciliar canons. It takes pains to show that nowhere in these sources is there a clear mandate to venerate images – and in some cases, the sources caution against it. For example, the text leverages St. Augustine’s warnings against pagan idol-worship and applies them to Christian image-veneration, suggesting the difference is only one of degree. It also compiles an anthology of patristic quotes that approve of images for teaching but do not mention honoring them (Libri Carolini - Wikipedia). In doing so, the Carolingians attempted to claim the mantle of “catholic” (universal) tradition for their position, painting the iconophiles as outliers. This contrasts with how the Byzantine defenders compiled their own florilegia of fathers supporting images (though many of those texts were of dubious or later origin). Essentially, both sides cherry-picked authorities – a reminder that the battle over images was also a battle over who spoke for Christian tradition. Modern historians note that the Carolingians had an impressive library and knowledge; the Libri Carolini shows a “better understanding of the Fathers of the golden patristic age” than either extreme, contending that iconoclasts wrongly claimed the Fathers were against all images, while iconophiles wrongly claimed the Fathers endorsed image-veneration (Libri Carolini - Wikipedia) (Libri Carolini - Wikipedia). This balanced claim underscores the Carolingian conviction that they alone truly understood and continued the authentic patristic line.

Doctrinally, one could critique the Libri Carolini for a certain narrowness or rigorism in its theology of art. While it correctly dismisses the worship of images, it perhaps underestimates the potential value of images in nurturing devotion (beyond mere instruction). The Eastern theologians, like John of Damascus, had articulated an incarnational principle – that because God took material flesh, material things (like images) can be honorable and even conduits of grace. The Carolingians, however, remained wary of confusing matter with spirit, fearing that any extra honor to images verged on superstition. Their viewpoint arguably hews closer to a strict reading of the Second Commandment (prohibition of graven images) than the nuanced Christological reasoning of the Greeks. In that sense, the Libri Carolini can be seen as theologically conservative, holding fast to a very spiritualized worship that minimizes physical intermediaries – an outlook that would later resonate with Reformers. Yet, unlike the most extreme iconoclasts, the Carolingians did appreciate the incarnational reality: they did not reject images outright, and they lavishly illuminated manuscripts and built artful churches in practice. In fact, Theodulf of Orléans himself sponsored one of the most remarkable artworks of the age – the mosaic of the Ark of the Covenant in his private chapel (Germigny-des-Prés) – which pointedly uses a non-figurative biblical image (the Ark) in place of the more typical Christian figural icons (File:Germigny-des-Prés (Loiret). (13607111463).jpg - Wikimedia Commons). This mosaic (see image below) symbolized God’s presence without depicting God or saints, aligning with Theodulf’s caution about not portraying the divine.

(File:Germigny-des-Prés (Loiret). (13607111463).jpg - Wikimedia Commons) Mosaic of the Ark of the Covenant (806) in the apse of Theodulf of Orléans’ chapel at Germigny-des-Prés (Frankish Kingdom). Theodulf, likely the author of the *Libri Carolini, chose this Old Testament image – flanked by angels – instead of depicting Christ or saints. The Latin inscription (bottom) exhorts the viewer to contemplate the Ark and pray to God, while remembering Theodulf. The mosaic’s iconography reflects a theology that avoids human images of the divine, consistent with the Libri Carolini’s caution against venerating icons (File:Germigny-des-Prés (Loiret). (13607111463).jpg - Wikimedia Commons) (File:Germigny-des-Prés (Loiret). (13607111463).jpg - Wikimedia Commons).*
In evaluating the Libri Carolini, scholars often marvel at its comprehensive scope and systematic approach. Thomas F. X. Noble, a historian of the Carolingian era, called it one of the fullest expressions of Carolingian theological thought, noting how it weaves together scripture, tradition, and Carolingian ideological aims () (). Its legacy is paradoxical: on one hand, it failed to carry the day in its own age, leaving hardly a ripple in official doctrine. On the other hand, its very existence testifies to the growing self-confidence of the Frankish church to interpret doctrine without deferring to Eastern or even papal precedence – a significant development in the lead-up to medieval Latin Christianity’s distinct identity. Furthermore, its rediscovery impacted the course of later Christian disputes about images, proving that the questions of the 8th century could echo loudly in the 16th.

In comparison to other Carolingian theological works, the Libri Carolini stands out for its polemical edge. Carolingian scholars like Alcuin of York or Paulinus of Aquileia also wrote treatises (for instance, against Adoptionism), but those were more directly pastoral and biblical, whereas Libri Carolini is an ambitious commentary on an ecumenical council’s acts. It has a conciliar and dialectical character – essentially a running critique – which is uncommon in Western theology at that date. In style, it might be likened to an extensive scholastic disputation avant la lettre. Indeed, one could see in it a precursor of the later medieval Scholastic method of sic et non (yes and no): it sets up the arguments of Nicaea II and systematically rebuts them, much as Scholastics would later set up objections and answer them. In this sense, the Libri Carolini was ahead of its time in method, if not in conclusion.

Conclusion

The Libri Carolini is a remarkable document at the crossroads of theology, politics, and art in the early medieval West. Born from the peculiar historical moment when Charlemagne’s Frankish kingdom sought to assert its doctrinal voice, it encapsulates the Carolingian middle way on images – accepting art’s instructional value while rejecting what was seen as idolatrous veneration. Its creation under Charlemagne’s patronage by Theodulf of Orléans and others exemplifies the heights of scholarship achieved in the Carolingian Renaissance, harnessed in service of contemporary ecclesiastical debates. Although the treatise’s immediate influence was minimal (due to its suppression in deference to the papacy), its eventual resurfacing had an outsized influence in later centuries, notably as a tool in Reformation polemics.

Today, the Libri Carolini invites us to reflect on how cultural and linguistic misunderstandings – such as the mistranslated acts from Greek to Latin – can lead to lasting theological divergences, and how leaders like Charlemagne navigated the complex relationship between secular authority and church doctrine. It also offers a case study in the use of patristic authority and biblical principle to critique contemporary practice, illustrating the continuity and discontinuity in tradition. Ultimately, even though the Western Church came to endorse the veneration of images in line with Nicaea II (something the Carolingians resisted), the Libri Carolini remains an invaluable witness to a distinct early medieval Latin perspective on Christian art. In its pages we find a scholarly and principled argument that struggled – unsuccessfully yet memorably – to balance reverence for the divine with caution against the seductions of material representation (Libri Carolini - Wikipedia) (Libri Carolini - Wikipedia). As such, the work holds a distinguished place in the history of theology and continues to be studied as a testament to the Carolingian commitment to orthodoxy as they understood it, and the rich intellectual world of Charlemagne’s court.

References

• Second Council of Nicaea, Acta (787). In Nicene and Post-Nicene Fathers, Second Series, Vol. 14. (For the decrees on icons and Frankish reaction)
• Freeman, Ann. “Carolingian Orthodoxy and the Fate of the Libri Carolini.” Viator 16 (1985): 65–108.
• Freeman, Ann. “Theodulf of Orléans and the Libri Carolini.” Speculum 32, no. 4 (1957): 663–705.
• Freeman, Ann, and Paul Meyvaert, eds. Opus Caroli Regis contra Synodum (Libri Carolini). Hannover: MGH Conc. II Suppl. 1, 1998. (Critical edition of the Latin text)
• Noble, Thomas F. X. Images, Iconoclasm, and the Carolingians. Philadelphia: University of Pennsylvania Press, 2009.
• O’Brien, Conor. “Empire, Ethnic Election and Exegesis in the Opus Caroli.” Studies in Church History 54 (2018): 90–119. () ()
• Mitalaité, Kristina. Philosophie et théologie de l’image dans les Libri Carolini. Paris: Champion, 2007.
• Theodulf of Orléans. Carolingian Oratory of Germigny-des-Prés (Mosaic Inscription), 806. (Latin inscription text: see Wikimedia Commons) (File:Germigny-des-Prés (Loiret). (13607111463).jpg - Wikimedia Commons) (File:Germigny-des-Prés (Loiret). (13607111463).jpg - Wikimedia Commons)
• John Calvin. Institutes of the Christian Religion, Book I, Chapter 11, section 14. (References to the Libri Carolini in Reformation argumentation) (Libri Carolini - Wikipedia)
• Pope Gregory the Great. Epistle to Serenus of Marseille (Reg. 11.10), c.600. (Source of the quote on images as “books for the ignorant”) (Libri Carolini - Wikipedia)