For various reasons, among them changes in the global higher education regime and competitive knowledge claims from other disciplines, the field of the history of sociology (HoS) has experienced an increased pressure to justify its own existence during the last decade. Positing that the best approach to justify the existence of a thing is to show its usefulness, the article discusses four types of claims to usefulness made by historians of sociology. The history of sociology can be said to be relevant in (I) shaping and maintaining the discipline's identity; (II) in providing a rich fund of teaching future sociologists; (III) in informing current research and theorizing; and (IV) in reflecting more broadly on the cultural status of sociology in modern societies. The article then assesses the potential and problems of aspiring a historical epistemology of sociology, a proposal made recently especially in German and Anglophone contexts to link the history of science with its philosophy in the sense described as type III. It concludes that selected principles or ideas of historical epistemology can be very fruitfully applied in HoS. However, the project of transferring the whole program of historical epistemology into HoS is bound to fail. Nonetheless, there is plenty of reason to continue conceiving of HoS as an integral part of sociology.