This chapter assesses the linguistic evidence of politeness in medieval Britain. The written sources are scarce, especially for the Anglo-Saxon period. An analysis of relevant lexical items suggests that in Old English, politeness in the modern sense did not play a significant role. Discernment politeness (i.e. the appropriateness of behaviour in given situations) was more important in a strictly hierarchical society, and in religious contexts there is evidence of a politeness of humility and gentleness. The influence of French on Middle English brought new concepts, in particular the concept of courtesy. Detailed case studies of Geoffrey Chaucer’s Canterbury Tales and of the anonymous poem Sir Gawain and the Green Knight show how this concept reflects a new type of courtly politeness.