The sociolinguistic geography of Morlaix in 1701 is far more complex than might be presumed. Close study of the documents that Lhuyd brought back from Northwestern Brittany – both those he wrote himself and those he collected – makes it plain that even during his sojourn abroad our antiquarian was surrounded by English speakers from Ireland, Cornwall and/or England. At some stage these people would have needed a phrasebook to understand the French and Breton speakers of Morlaix. These language contacts, specific to Morlaix, may have been decisive in spurring Lhuyd to pen his French-Breton dialogues. The language engineered for that purpose reflects how British and Irish elites interacted with a French- or Breton-speaking middle class. Such a text written in Breton is truly exceptional for that period. It leads us to reconsider what kind of Breton was spoken during the seventeenth and eighteenth centuries in the towns of Lower Brittany, and to appreciate the full extent to which several variations of Breton coexisted among different urban groups.