Magnus Ryan works on Roman-canon law in the later middle ages and its place in the western tradition of political ideas until the seventeenth century. His doctoral thesis was devoted to the Liber or Libri feudorum, and to how the glossators and commentators responded to, deployed and augmented the feudal law in the later middle ages. He has held research fellowships at St John’s College, Cambridge and All Souls College, Oxford, and has worked on numerous occasions at the Max Planck Institut für europäische Rechtsgeschichte in Frankfurt am Main, as well as at the former Max Planck Institut für Geschichte in Göttingen.  He gave the Carlyle lectures at Oxford University in 2004 and has been visiting professor at the faculty of law of Università di Roma 3, and the Centre d'étude des normes juridiques at the Ecole des Hautes Etudes He was a university lecturer at the Warburg Institute between 1999 and 2006, and is currently a university lecturer in the Faculty of History in Cambridge, where he is a fellow of Peterhouse. He remains a fellow of All Souls, Oxford.

Publications

• "Ius Commune Feudorum in the Thirteenth Century,” in …Colendo iustitiam et iura condendo… Federico II Legislatore del Regno di Sicilia nell’Europa del Duecento.  Per una storia comparata delle codificazioni europee, ed. A. Romano (Rome 1997), pp. 51-65.
• “The Oath of Fealty and the Lawyers,” in Politische Ideen im Mittelalter.  Theorie und Wirklichkeit der Macht (Veröffentlichungen des Max Planck Instituts für Geschichte), eds. J. Canning, O.-G. Oexle, pp. 209-226.
• “Bartolus of Sassoferrato and Free Cities”, The Alexander Prize Essay for the Royal Historical Society, 1999, printed in Transactions of the Royal Historical Society 2000, pp. 65-89.
• “Rulers and Justice, 1200-1500,” in The Medieval World, ed. P.A. Linehan, J.L. Nelson (London 2001), pp. 503-517.
• “Feudal Obligation and Rights of Resistance,” in Die Gegenwart des Feudalismus, ed. N. Fryde, P. Monnet, O-G. Oexle, (Göttingen 2002), pp. 51-78.
• ­“Freedom, Law and the Medieval State,” in States and Citizens, ed. Q. Skinner, B. Stråth, (Cambridge 2003), pp. 51-62.
• “Widerstandsrecht und Lehnswesen”, in Wissen, Gewissen und Wissenschaft im Widerstandsrecht (16.–18. Jh.) / Sapere, coscienza e scienza nel diritto di resistenza (XVI–XVIII sec.), ed. K-H. Lingens and A. de Benedictis, (Studien zur europäischen Rechtsgeschichte 165, Frankfurt am Main 2003), pp. 49-80.
• Maitland:  Trust, State and Corporation (ed., with David Runciman), Cambridge Texts in the History of Political Thought (Cambridge 2004).
• Art. “Glossators and Postglossators,” in P. Crane and J. Conaghan (eds), The New Oxford Companion to Law (Oxford 2008), cols. 503-5.
• “Zur Tradition des langobardischen Lehnrechts,” in G. Dilcher and D. Quaglioni (eds), Die Anfänge des öffentlichen Rechts, 2. Von Friedrich Barbarossa zu Friedrich II., (Bologna/Berlin, 2009), pp. 225-245.