Constitutiones of King Roger II, Prologue
Vat. lat. 8782, fol. 91r

Relationship of the Ius commune and Local legislation (Ius proprium)

Ken Pennington, 'The Birth of the Ius commune: King Roger II's Legislation,' Rivista internazionale del diritto comune 17 (2006)  1-40

 Ken Pennington,  "The 'Big Bang': Roman Law in the Early Twelfth-Century,"Rivista internazionale di diritto comune 18 (2007) 43-70

Ken Pennington, 'Roman Law at the Papal Curia in the Early Twelfth Century,' Canon Law,  Religion, and Politics: Liber Amicorum Robert Somerville, edited by Uta-Renate Blumenthal, Anders Winroth, and Peter Landau (Washington, DC: The Catholic University Press of America, 2012) 233-252

Ken Pennington, 'The Beginning of Roman Law Jurisprudence and Teaching in the Twelfth Century:  The Authenticae,' Rivista internazionale di diritto comune 22 (2012) 35-53.

Chris Wickham, Courts and Conflict in Twelfth-Century Tuscany (Oxford: Oxford University Press, 2003) 2 'It can, of course, be argued that law was irrelevant .  .  . and that Romanist scholarship was an almost entirely abstract science, a set of commentaries on a quasi-holy text, .  .  . as divorced from practical knowledge as any Parisian theological treatise.'