Disciplinary measures and, more broadly, the pursuit of upholding the quality of professional performance are not new but have a long history. Although the disciplinary processes, disciplinary law and the disciplinary measures imposed in the past were, in principle, intended to ensure a certain degree of decency (cf. the honour of the rank), the centre of attention seems to have now shifted to ensuring a high degree of professional expertise, including non-ethical regulation and enforcement. This contribution addresses the evolution and development of the way one attempted to guarantee the professional standards of medical practitioners, lawyers and notaries in legal history. Disciplinary law is one of the roads pursued for this purpose. In discussing these professions, their origins, their (legal) development throughout history (with an emphasis on the Modern Age) and the current state of affairs will be dealt with. Some comparative remarks then follow concerning the differences and similarities in the way these professionals sought to monitor the quality of their professional performance.