This paper analyses lexical features in letters written to and by Margaret Paston, using Fairclough’s (1992) three-dimensional framework for discourse analysis. Historical pragmatics, as a relatively new field, is open to the development of new methodologies and the adaptation of established ones. Although Fairclough’s methodology is intended as a systematic way of approaching modern text, it is shown to be relevant and useful in historical work. The letters are analysed in context, with reference to the discursive practices (production, distribution, and consumption of text) and social practices of the fifteenth century. The analysis shows that Margaret occupies a powerful position within her family and the community.