The object of this article is to draw attention to an area of European legal history that I think deserves more investigation. It is the change in legal practice caused by the transition from the diffused, undifferentiated, customary law of the earlier middle ages to the various forms of expert, esoteric, professional law that dominated the higher courts of the later middle ages. The suggestion that this has not been much studied may seem odd but, though much has been written on the new study of Roman law, those who work on it have tended to concentrate on the intellectual achievements of the glossators and post-glossators, rather than on practice. Practice in canon law has received more attention, notably from legal historians trained in the Anglo-American tradition, but this has not focused closely on twelfth-century origins. The beginnings of English common law have also been much studied and, since it started off as largely a matter of procedures, that has indeed meant looking at practice. The traditional teleology of legal history has, however, prevented much cross-fertilization with the history of other legal systems. One example of the consequent detachment of English legal history is the assumption of some English legal historians that Roman law procedures were followed in what they often characterize simply as “the Continent” more generally and earlier than seems to have been the case in most areas north of the Alps. Both in England and elsewhere many legal historians concentrate on the period from the thirteenth century on, when sources become more plentiful. Meanwhile, social historians of early medieval western Europe, including England, have argued—to my mind successfully, though I am hardly unprejudiced—that early medieval law was not just a weak, ritualized, and irrational response to feuds and violence, but their investigations tend to stop before the professionals took over. The result is that, apart from recent pioneering work on twelfth-century Tuscany by Chris Wickham, the transition in court practice outside England has been neglected.