Chaucer’s London, with a population of around 50,000, had experienced considerable immigration from the Home Counties, Midlands and elsewhere in England in the fourteenth century. In addition to accommodating such incomers, Londoners would also regularly come across Scots, Welsh, Irish, Flemings, Florentines, and Hanseatics. This was, then, a city of multiple identities and shifting linguistic variety. Variation and change therefore characterised London texts and the development of London English during the late medieval period. Chaucer was particularly sensitive to such variation – to geographical distinctions and to emerging social differences articulated linguistically: this shows in his appreciation of the position of French in England as well as of the various ‘Englishes’ that he would have encountered. Chaucer’s verse reveals a writer exceptionally aware of the languages around him, whether he is contrasting the Knight with the Miller, or re-performing Northern speech in his Reeve’s Tale. All in all, the rich range of socio-linguistic usages available in the language of London gave Chaucer numerous opportunities for the literary invention that typifies his achievement.