Historical politeness studies provide specific challenges for the researcher in terms of both methodologies and data. This chapter introduces a distinction between approaches that focus on the use of politeness (i.e. on linguistic elements that convey politeness) and those that focus on the mention of politeness (i.e. on elements that are used to talk about politeness, the metadiscourse of politeness). This distinction is set in relation to the distinction between quantitative and qualitative approaches to politeness, and to the distinction between first-order and second-order approaches. The chapter also discusses the data problems of historical pragmatics in general and historical politeness research in particular, and it describes the shift in such research from apologetic uses of what is seen as imperfect data to an appreciation of the pragmatic potential of a large variety of sources including in particular fictional texts.