The English Magna Carta (1215) has long stood as a symbol of human liberty and the rule of law. This Article investigates its intellectual origins, suggesting the existence of possible influence on the Charter by the contemporary ius commune, the amalgam of Roman and canon laws that had emerged in consequence of the revival of legal studies on the Continent in the twelfth century. Comparing the substance of over half of the chapters with the contemporary ius commune, the Article demonstrates that many similarities existed. Accepting the possibility of use of Continental sources in drafting the Charter helps explain otherwise puzzling features in it. It also accords with common patterns in legal development at the time.