We provide an overview of three ways in which the expression "Historical epistemology" (HE) is often understood: (1) HE as a study of the history of higher-order epistemic concepts such as objectivity, observation, experimentation, or probability; (2) HE as a study of the historical trajectories of the objects of research, such as the electron, DNA, or phlogiston; (3) HE as the long-term study of scientific developments. After laying out various ways in which these agendas touch on current debates within both epistemology and philosophy of science (e. g., skepticism, realism, rationality of scientific change), we conclude by highlighting three topics as especially worthy of further philosophical investigation. The first concerns the methods, aims and systematic ambitions of the history of epistemology. The second concerns the ways in versions of HE can be connected to versions of naturalized and social epistemologies. The third concerns the philosophy of history, and in particular the level of analysis at which a historical analysis should aim. © 2011 Springer Science+Business Media B.V.