Bartholomew the Englishman

On Leprosy

Introduction by Juris Lidaka, Courtney Roby, and Rega Wood

Bartholomew says: "Leprosy is a corruption of the organs and humors, having its beginning from vessels and its completion in fountains or outside the vessel. When the humor of nutriment is corrupted, the organs are easily corrupted, as they are fed from the humors. Every [kind of] elephantiasis or leprosy, according to Constantine [], has its beginning principally from the corruption of black bile. Therefore Constantine says that leprosy is a cold dry affliction, originating from black bile which is tightened and rotten, appearing on the surface of the body. For it originates from the four humors when they are rotten, yet tightened and corrupted, and transformed into black bile, as the same man says in the same place. Rotting of the humors with which black bile is mixed, on account of its cold dry quality that resists rotting, cannot occur in the veins or in vessels, until it is integrated in the body. It causes a delay in the limbs in which the rotting occurs, from which leprosy itself follows."

Original Latin

Constantine the African

Bartholomew follows in the tradition of Greek and Arabic medical knowledge made available to Europeans by Constantine the African. Constantine was born in Carthage around 1015-20 CE. Carthage was under Arab rule, but Constantine was a Christian and learned Latin.

Later in Constantine's life (c. 1070-1080?), he entered the monastery founded by St. Benedict at Monte Cassino. There, he translated many medical works from Arabic into Latin. Quite a few of these were Greek works that had previously been translated into Arabic. The Greek authors were known, but Europeans owed their access to them to Constantine’s efforts.  Constantine's sources were Arabic physicians.  In the case of leprosy, Ali ibn al-Abbas al-Magusi was their major source, many of whose works were translated by Constantine.

In this text Bartholomew follows Constantine, one of his chief medical sources. After describing the forms leprosy can take, he notes the vectors of infection and their recommended treatments. Oddly, Bartholomew does not discuss leper houses or hospitals, where lepers were largely isolated from the general population.

Confusion about Causes

Not knowing about the bacillus that causes leprosy, Bartholomew can identify the sickness only by the symptoms.

When discussing the causes of leprosy, Bartholomew considers contagion first but then he discusses other sources of disease that produced humoral imbalance:

  • tainted food
  • poisoned air
  • reptile bites.

Most significantly from a political point of view, medievals thought that leprosy could be caused by divine displeasure. Thomas ŕ Becket, for example, warned King Henry II that he might be struck by leprosy for his sins.

Social Responses to Leprosy

The social response to leprosy varied. Some Christians told sinners they might contract the disease as a punishment for their offenses. Other Christians made a religious practice of showing compassion for lepers by bathing and embracing them.

Two thirteenth-century saints were famous for serving lepers: Saint Louis of France and St. Francis of Assisi. Francis’ Testament begins by explaining the sight of leper was offensive to him only while he was in sin:

“This is how the Lord gave me, brother Francis, the power to do penance. When I was in sin the sight of lepers was too bitter for me. And the Lord himself led me among them, and I pitied and helped them. And when I left them I discovered that what had seemed bitter to m e was changed into sweetness in my soul and body. And shortly afterward I rose and left the world.”1

Other Christians moved by compassion founded leprosaria. Lanfranc of Bec, a great Archbishop of Canterbury (d. 1089), founded a famous leprosarium at Harbledown near Canterbury, which was one of the first independent hospitals in England.

No doubt much good was done by such hospitals, but they also isolated lepers (and people suspected of having leprosy) from the rest of society. In 1175, the English church decreed that lepers could not live among the healthy. So the leprosaria were a mixed blessing: they reflect both on people’s horror as well as their compassion.

leprosaria: communities with a care center or hospital for lepers apart from the rest of society

1. Courtesy of the Medieval Sourcebook.


C. Burnett, The Introduction of Arabic Learning into England, London 1997. 

Constantine the African and Ali ibn al-Abbas al-Magusi: The Pantegni and Related Texts, ed C. Burnett and D. Jacquart  Studies in Ancient Medicine, vol. 10. Leiden1994.

C. Rawcliffe, Leprosy in Medieval England, Woodbridge, Suffolk and Rochester, NY, 2006.