Online Medieval Sources Bibliography

An Annotated Bibliography of Printed and Online Primary Sources for the Middle Ages

Source Details

Stevens, Wesley M. ed., De Computo (Turnhout: Brepols Series)

Text name(s): De Computo

Number of pages of primary source text: 121


Dates: 820 - 820

Archival Reference: 

Original Language(s): 

  • Latin


  • Original language included.

Translation Comments: 

Geopolitical Region(s): 

  • Germany
  • Europe


Record Types: 

  • Treatise - Scientific/Medical
  • Dialog

Subject Headings: 

  • Grammar / Rhetoric
  • Education / Universities
  • Philosophy / Theology
  • Science / Technology
  • Science - Mathematics
  • Science - Astronomy


  • Index
  • Glossary
  • Introduction


The title of Hrabanus’ treatise refers to the art of reckoning at all levels from the initial mastery of numbers and arithmetic to the mastery of methods for explaining the whole cosmos. In this treatise, Hrabanus combines theology and mathematics, forging a methodology grounded in both revelation and reason. In 96 chapters organized in 5 sections and cast in the form of a dialogue, Hrabanus addressed problems posed by the calendar, explaining how to reckon the moveable feasts of the year. Designed for the classroom, the work shows how the teacher can lead a student gradually from the simplest of arithmetical problems to the more arcane matters of planetary motion. Close attention is finally paid to the meaning and reckoning of time itself. Hrabanus’ principal sources are such works of Bedae as De temporibus (concerning times), De Natura Rerum (Concerning the Nature of t=Things) and De temporum ratione (Concerning the Concept of Times).

Introduction Summary: 

In his introduction (33 pages), the editor opens with a portrait of Hrabanus Maurus not as an abbot but as a teacher and author. Locating Hrabanus within the context of liberal arts, the editor offers a comprehensive definition of the activity of computing (Computus) from which Hrabanus takes the title for his work. What follows is a broad survey of computistical writings from the Julian reform (45 B.C.) to the essays of Beda (A.D. 725). The editors then discusses the composition of Hrabanus’ tract on computation, its sources, date of composition, manuscript tradition and modern editions.

Cataloger: AT