This latest collection of studies by James Brundage deals with the emergence of the profession of canon law and with aspects of its practice in the period from the 12th to the 14th centuries. Substantial numbers of lawyers systematically trained in canon law first appeared in Western Europe during the second half of the 12th, century and in the 13th they began to dominate the hierarchy of the Western church. By 1250 canon law had grown into something more than a profitable occupation: it had become a recognizable profession in the strict meaning of the term as it is still used today. University law faculties trained aspiring canonists in the mysteries of their craft and put them through intellectually demanding exercises that terminated in a formal examination before they received their degrees. Judges in church courts formally admitted them to practice after verifying their educational qualifications and administered prescribed rules of conduct. Particular topics are the canonists’ system of legal ethics, the education and training of canon lawyers in university law faculties, and some fundamental features of the professional practice of canon law, both in medieval Europe and in the crusading states of the Levant.