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Bio-Bibliographical Guide to Medieval and Early Modern Jurists

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Report No. a254

Guillelmus Durandus



Alternative Names

Durand, Guillaume (LC); William Duranti; the Speculator; William Durand; Gulielmus Durantis Senior; Guilelmus Durantis the Elder; Wilhelm Durand; Guillaume Durand



Famous author of the Speculum iudiciale, the most widely used procedural treatise of the Middle Ages. He was born near Beziers in Southern France, in 1236. He studied canon law at Bologna under Bernardus Parmensis and later taught at Modena. Pope Clement IV (1265–68) made him auditor generalis of the Rota, which gave him the practical experience reflected in his chief work. G. attended the Second Council of Lyon in 1274 and later wrote a commentary on the council’s constitutions. The peak of his administrative career was reached when he became rector generalis of the papal states in 1278, which he then exchanged for the rectorship of the new French papal provinces (1281–82). Guillelmus became bishop of Mende in 1286. He died at Rome ten years later.



No. 1

Repertorium iuris canonici. 1st ed. 1271; 2nd ed. before 1279.

No. 2

Speculum iudiciale, 1271–91. 1st version 1271–1276; revised 1287–1291.

No. 3

In sacrosanctam concilium Lugdunense commentarius, c.1293–94. on the constitutions of the Second Council of Lyon (1274).


Text(s) – Manuscripts

No. 1

Repertorium iuris canonici.


München, BSB Clm 13087 (Can be downloaded. Schulte QF 2.152 lists other manuscripts.)


Text(s) – Early Printed Editions

No. 1

Repertorium iuris canonici.

Early Printed Editions

Repertorium iuris canonici. Roma, 1474.


Repertorium iuris canonici. Venezia, 1496. Later editions appended the text to the end of the Speculum iudiciale.

No. 2

Speculum iudiciale, 1271–91.

Early Printed Editions

Speculum iudiciale. Frankfurt, 1602.

No. 3

In sacrosanctam concilium Lugdunense commentarius, c.1293–94.

Early Printed Editions

In sacrosanctam concilium Lugdunense commentarius. Fano: S. Maiolo, 1569 (online).



J. Viejo-Ximénez, ‘Guillermo Durando’, in Juristas universales 1.472–4.

R. Aubert, ‘Guillaume Durant évêque de Mende, dit “le Speculateur” († 1296)’, in DHGE (1988) 22.891–92.

L. Boyle, ‘The Date of the Commentary of William Duranti on the Constitutions of the Second Council of Lyons’, BMCL, 4 (1974) 39–47.

M. Bertram, ‘Zur wissenschaftlichen Bearbeitung der Konstitutionen Gregors X.’, QF, 53 (1973) 459–67.

J. Brundage, Medieval Canon Law and the Crusader (Madison WI 1969) 109–10, 129–30.

L. Falletti, ‘Guillaume Durand’, in DDC (1953) 5.1014–75.

V. Leclerq, ‘Guillaume Duranti, Évêque de Mende, surnommé le Spéculateur’, in HLF (1895) 20.411–97.

J. von Schulte, QL 2.144–56.