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MS 129: Astronomical treatise known as Theorica Planetarum by an unknown author, 15th century

Identifier: MS 129


This 15th century manuscript is a copy of an astronomical text known as the Theorica Planetarum, which was incredibly popular in the medieval period, and survives in over 200 manuscript copies. There has been much debate on the authorship of this text, and it has been attributed to Robert Grosseteste, and also Gerard of Cremona. However, it seems most likely that this text, of which MS 128 is a copy, is the work of an anonymous teacher of astronomy from about the mid-13th century. Given the apparent popularity of this particular text, evidenced by its supplementary inclusion in Sacrobosco's works that had become established as the core of the 13th-century astronomical curriculum, this Theorica Planetarum most likely was written shortly after the mid-13th century in a place where Sacrobosco's texts had already risen to prominence in the field of astronomy.

The text starts on f. 1r with the following words: Circulus ecentricus vel egresse cuspidis, and ends with: bicubitum vel tricubitum vel majoris quantitatis. Explicit theorica planetarum. Finis. on f. 14v.


Very fine italic script.


Rubrics of Roman capitals in red, and one good burnished gold initial with vine-leaf scroll.


  • Creation: 15th century

Language of Materials


Conditions Governing Access

The collection is open to all. The manuscripts can be consulted in the Centre for Research Collections, Edinburgh University Main Library.


1 bound MS volume

Custodial History

Italian script and illumination, no marks of ownership whatever. The number 1064 is on a label on the cover.

Previous title

Title given to the manuscript in Catherine Borland’s catalogue: Theorica planetarium (Groseteste).

Previous reference

Laing 162


O. Pederson, 'The Origins of the Theorica Planetarum', Journal for the History of Astronomy Vol 12 (1981), pp. 113-23.

Physical Facet

Material: Vellum

Binding: Modern, lettered 'Theor. Plan.'

Collation: a4, b2 (wants 1 and 2), c4, d4=14.


17.15 cm X 12.07 cm


Secundo folio: [E]piciclus sive orbis

Foliation and number of lines to a page: ff. 14, 23 lines to a page.

Repository Details

Part of the University of Edinburgh Library Heritage Collections Repository

Centre for Research Collections
University of Edinburgh Main Library
George Square
Edinburgh EH8 9LJ Scotland
+44(0)131 650 8379