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.

6 thoughts on “Ego Constantinus africanus montis cassinensis monacus

Leave a Reply to “Once settled in this monastery, he translated a great number of books from the languages of diverse peoples”: The Constantinian Corpus – Constantinus Africanus Cancel reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s