“In Latin books, I found no author who gave certain and authentic information; therefore, I turned to the Arabic language…”

In our previous post, we stated that Constantine the African was one of the most important authors in the Latin (and thus the Western) medical tradition. But why? What did Constantine’s works offer that earlier texts in Latin– medical works that had been translated from Greek into Latin in late antiquity, for example– had lacked? This question takes us into the heart of the works that Constantine produced, the way he produced them, and the particular place in history that Constantine occupied. The answer, briefly, is that Constantine’s skillful and well-positioned translations drew on centuries of medical scholarship in the Islamic world that synthesized and surpassed the findings of the ancient medical tradition.

In antiquity, Greek authors– and the Greek-speaking Roman physician Galen (d. ca. 216 CE) above all– had produced a sophisticated body of medical knowledge, a set of texts that made substantial improvements upon earlier knowledge of anatomy, physiology, and, to a somewhat lesser extent, therapeutics. In the 600 years after Galen’s death, the production of scientific and medical works in Greek waned to a trickle, but this medical tradition was taken up with avidity by writers in Arabic and Persian after the rise of Islam in the seventh century. More than merely repeating or harmonizing what Galen had already said, this Islamic medical tradition added to and even disputed Galen’s findings in works of considerable sophistication.1 It described illnesses, such as smallpox, that had only been mentioned briefly (or not at all) by Galen; attempted to resolve inconsistencies in his works; and even disparaged Galen’s philosophical pretensions.

Nor was this all. Islamic writers, writing in the richest, most vibrant cities in the Islamic world (and indeed, some of the greatest cities in the Middle Ages), had access to medicinal substances and medical learning that Galen did not. Where cane sugar had been known to ancient medical writers as a rare import, it was readily available to Islamic physicians; where Roman scholars had some vague notions of India, scholars in the Islamic tradition were able to consult Arabic translations of Sanskrit medicine. The medical works that were produced in the Islamic world, then, were not warmed-over compilations of ancient medicine, but works that often broadened the tradition with new resources, observations, and reasoned debate.

Constantine the African’s translations played a central role in introducing medicinal substances from Islamic medicine such as sugar cane into the Latin medical tradition, here pictured in a thirteenth-century copy of the Tractatus de herbis, an expanded version of the Salernitan pharmaceutical treatise, Circa instans. British Library, MS Egerton 747, f. 106r.

On the other hand, the very vitality of the Islamic medical tradition posed its own set of challenges. After short centuries of conquest, Islamic rule was firmly established from the Iberian peninsula (modern Spain) in the west to beyond Persia in the east, and medical writers across this broad territory developed their own traditions. We can easily understand why: practitioners in Córdoba might need to treat illnesses differently from those encountered in Ghazna (in modern Afghanistan) and might draw upon different plant, animal, and mineral substances from which to confect remedies. What resulted was not unchecked chaos: medical scholars shared the same theoretical and methodological framework: Islamic medical writers agreed on the fundamental importance of the four humors, for example, and that humoral imbalance was one of the principal causes of disease. Once you scratched the surface of this tradition, however, its complexities became apparent: Arabic terminology jostled with loan words from Greek, Persian, Syriac, and even Sanskrit, while authors gave varying explanations and remedies for a wide range of illnesses.

Islamic medicine, then, was always characterized by a tension between its centrifugal tendencies and the desire of some scholars to make its complexities orderly and systematic. The great systematizer ʻAlī ibn al-ʻAbbās al-Majūsī (d. after 977), for example, who spent much of his career in Shiraz (in modern Iran), self-consciously tried to improve the overwhelmingly long and disorganized works of his predecessors with a rigorously organized overview of medical theory and practice in twenty books. But medical scholarship did not stand still while al-Majūsī worked, and medical scholarship also flourished elsewhere, as in the vibrant medical tradition of the North African city of Kairouan. Where al-Majūsī’s overview of medicine sought to systematize Islamic medicine, the Muslim physician Ibn al-Jazzār (d. ca. 979) put forward his own view of medicine in works that explained diseases and therapeutics for lay readers while also subtly delineating the moral ramifications of health and disease.

In the tenth and eleventh centuries, the Islamic territories covering a huge swathe of Eurasia, North Africa, and beyond were renowned for their power, wealth, and cultural refinement. But even more than the breadth of the territory controlled, however, the vitality of Islamic civilization is suggested by the fact that centers of major cultural importance could be found at opposite ends of this territory, from Córdoba in Al-Andalus (now modern Spain) to Ghazna (Ghazni, in modern Afghanistan). Map © Ian Mladjov

In contrast with the Islamic medical tradition, the Latin medical tradition was a far more modest affair. The Benedictine Rule, which structured monastic life for much of the Middle Ages, enjoined the care of the sick, but few monasteries took this as encouragement to systematically collect and study the works of medicine then available. Some medical practitioners were highly skilled (and those in Salerno in southern Italy were especially famed), but few efforts had been made before the eleventh century to harmonize their insights with theoretical works of ancient medicine. There can be little surprise, then, that when Constantine the African traveled from North Africa to southern Italy in the mid-eleventh century, he was unimpressed by what he found. What is likely to be one of his earliest works gives his appraisal: he had looked for a book on urines in Latin, Constantine explained, but found no author who gave “certain and authentic information,” and so he turned to Arabic instead.

As in his work on urines, Constantine’s other texts describe the difficulty of mastering medicine from Latin texts in vivid detail. Here, in his translation of a work on fevers (the Liber febrium) from a work of Ishaq al-Isra’ili’s, Constantine explains that the sad state of his student John (including “continual tears” and “the extreme scarcity of want”) had finally convinced him to translate a work on the subject. Kassel, MS Med. 15, f. 1r.

But for all of their virtues, presenting Arabic texts to Latin readers in a comprehensible way was a tall order. For one, Constantine was compelled to bring the rich and diverse Islamic medical tradition into some kind of harmony. At the same time, Constantine had to make these works accessible to his Latin readers. In the Pantegni and the Viaticum, two of his major translations, Constantine was judicious– and sometimes even severe– in pruning what he found in al-Majūsī’s systematized overview of Islamic medicine and Ibn al-Jazzār’s handbook of practical medicine, respectively. At times, Constantine was meticulous in rendering his sources into pithy Latin. In other cases, his compressions are startling: in translating the Viaticum, for example, Constantine occasionally leaves out the quantities in his medical recipes! But despite his omissions– and we will discuss the significance of Constantine’s omissions of the names of al-Majūsī, Ibn al-Jazzār, and his other Arabic sources in a later post– Constantine made a huge amount of medicine accessible and comprehensible to his contemporaries and successors.

When we consider the comprehensive body of texts that Constantine produced (the topic of next month’s post) and the specialized vocabulary he constructed to render them into Latin (which we will also address soon), it is perfectly comprehensible that generations of earlier scholars claimed, with some grandiosity, that Constantine had taught his contemporaries to speak. It might be more accurate, however, to claim that his copious translations presented Latin readers with a synthesis of some of the most refined works of medicine then in existence.

Further Reading:

  • Françoise Micheau, “‘Alī ibn Al-‘Abbās al-Maǧūsī et son milieu,” in: Constantine the African and ‘Ali ibn al-Abbas al-Maǧusi: The ‘Pantegni’ and Related Texts, ed. Charles Burnett and Danielle Jacquart, Studies in Ancient Medicine 10.  (Leiden: Brill, 1994), pp. 1-15.
  • Francis Newton, “Arabic Medicine and Other Arabic Cultural Influences in Southern Italy in the Time of Constantinus Africanus (saec. XI²),” in Between Text and Patient: The Medical Enterprise in Medieval and Early Modern Europe, ed. Florence Eliza Glaze and Brian Nance, Micrologus’ Library, 30 (Florence: SISMEL/Edizioni del Galuzzo, 2011), pp. 25-55.
  • Emilie Savage-Smith, ‘Were the Four Humours Fundamental to Medieval Islamic Medical Practice?’ In: The Body in Balance: Humoral Theory in Practice, ed. by Elisabeth Hsu and Peregrine Horden (Oxford: Berghahn Books, 2013), pp. 89–106.

1. By convention, modern scholars refer to medicine under Islamic rule as “Islamic,” even though Christians and Jews also played a major role in the tradition. Non-Muslims, in fact, wrote a number of the texts that Constantine translated. For further discussion, see Peter E. Pormann and Emilie Savage Smith, Medieval Islamic Medicine, Georgetown University Press (Washington, DC: 2007). 

Ego Constantinus africanus montis cassinensis monacus

Constantinus Africanus (Constantine the African) is likely the most famous medieval writer most people have never heard of. At latest count, we can identify at least 1000 extant manuscript copies of his three dozen writings on various aspects of medicine. Those writings, collectively, probably comprise over one million words. To put that in perspective, the most famous Benedictine monk of the Middle Ages, Benedict of Nursia, is represented in only about 300 extant copies of his Rule describing the monastic life. Most of Constantine’s contemporary writers at Monte Cassino, the motherhouse of the Benedictine order, are known from only a handful of extant copies.

So who is Constantine the African? And why are we launching this blog devoted to him and his works? First and foremost, Constantine was the first to render a major body of Arabic science into Latin. Yes, a few works of mathematics and astronomy had become known in Europe in the 10th century. But no one had yet attempted what Constantine did: bringing a whole science, from introductory textbooks to works of great complexity, into the Latin language. Once translated, these works could—and did—circulate all over Europe. They transformed medical theory and practice in the lands we think of as western Europe, giving it a medical vocabulary and certain common concepts that we can still recognize in biomedicine today.


This is from the preface to Constantine’s translation of Isaac Israeli’s (d. 932) book on urines. In the 4th and 5th lines, Constantine identifies himself: “Quem ego constantinus affricanus montiscassinensis monachus. latinȩ linguȩ ad transferendum destinaui dare” (“which [book] I, Constantine the African, monk of Monte Cassino, committed myself to translate into the Latin language”). Source: Vatican, Biblioteca Apostolica Vaticana, MS Urb. lat. 1415, f. 1v (detail).

In several of his writings, Constantine identified himself with the title we’ve used here: Ego Constantinus africanus montis cassinensis monacus. “I, Constantine the African, monk of Monte Cassino.” Constantine’s self-naming raises a host of intriguing questions. All evidence suggests that he did indeed come from “Africa,” which here means the North African territory of “Ifriqiyah,” and Constantine appears to have come from the territory of modern Tunisia in particular. Ifriqiyah had come under Muslim rule in the eighth century, as part of the general expansion of Islam across North Africa. But what can we infer from the name “Constantine”? It was, after all, the name of one of the most famous converts in Christian history, the fourth-century emperor Constantine. Was Constantine, then, an Arabic-speaking Muslim who converted to Christianity? Or did Constantine come from an Arabic-speaking Christian community in North Africa? Scholars have been unsure how to untangle this aspect of Constantine’s background, though we will suggest a solution to this puzzle in a later post.

What matters for today is that our Constantine was a native Arabic speaker. And he was thoroughly immersed in Arabic medicine. In later posts, we’ll talk more about the period of efflorescence in Arabic medicine that Constantine was able to draw upon when he crossed the Mediterranean in the eleventh century, bringing a cache of medical books with him (at least one of which was partially lost). In fact, as we’ll show, Constantine captures, in his own life story, larger trends unfolding at the time that would bring the economies and cultures of the Islamic, Christian, and Jewish societies in the Mediterranean more tightly into contact.


In this passage from Book I of the De melancholia (On Melancholy), a translation of Ishaq ibn ‘Imran’s treatise on the same topic, Constantine follows his source in identifying “the sudden loss of his learned books” as the reason someone might fall into the despair of melancholy. Source: London, British Library, MS Burney 216, f. 95ra (detail).

So, why launch this blog now? First of all, today, the 22nd of December, is Constantine’s obit day—the day his death was celebrated at the Abbey. One of the few pieces of concrete biographical information we have for him was the entry of his name into Leo Marsicanus’s calendar at Monte Cassino, listing his death date as December 22. In what year that happened, we’re not sure. It would have been before 1098 or 1099, the date of the calendar, though beyond that we can’t be more precise. He was said to have “died full of days,” and from his surviving works we can see what extraordinary success he had in laying the foundations for a full curriculum of medical learning.


The Cassinese Calendar, written at Monte Cassino in 1098-1099, under the direction of Leo Marsicanus, who first started the monastery’s chronicle. The second line of this entry for the 22nd of December (the 11th kalends of January) indicates the date of death for Constantinus monachus medicus. Source: Vatican, Biblioteca Apostolica Vaticana, MS Borg. lat. 211, f. 13r (detail).

A bigger question is why, if Constantine has been invisible for so long, is he suddenly coming into view? There are a lot of reasons for this, some having to do with the recent growth of history of medicine as a major subdiscipline in medieval studies, some having to do with the amazing new possibilities for manuscript research that allow us access to so many copies of Constantine’s still-unedited works. One reason we are particularly delighted to share our new understanding about Constantine in this blog is because in his life story and in his widespread effects on European culture, he gives us the opportunity to see a “global Middle Ages.” Constantine’s own travels may have been confined to the Mediterranean. But the medical system he brought into Latin drew upon medical theory first articulated in antiquity but expanded and refined in the Islamic world. And it drew on the pharmaceutical lore of medical practitioners across central Eurasia, North Africa, and beyond.

This blog is co-authored by Monica Green and Brian Long. We are both historians of medicine and are both editing and studying Constantine’s many writings. We will be joined from time to time by guest bloggers as well. Our aim is to begin to share our findings about Constantine: new manuscripts we’ve discovered; new information about Constantine’s Arabic sources; new leads about the impact of Constantine’s work in transforming the landscape of learned medicine in Europe. Almost every aspect of medicine would indeed change under Constantine’s influence. The life and works of this singular African monk therefore afford us the opportunity to peer into the heart of one of the most transformative periods of history.

Further Reading:

There isn’t a lot published on Constantine the African yet, and as we’ve noted, most of his works have not yet been edited, let alone translated into modern languages. Here are a few publications that can give you a hint of how interesting his life and times were.