History of Medieval Canon Law.
This link opens in a new window
Washington, DC: Catholic University of America Press, 1999-present. 4 volumes published.
Vol. 1 (ca. 400-1140); vol. 2 (1140-1234); vol. 3 (Early Middle Ages); vol. 4 (Byzantine and Eastern, to 1500).
When complete, this series will be the major secondary source about canon law up to 1500. It includes essays by different canonists.