This paper is concerned with the transformation in the Middle English Partonope of Blois of French place-names that appear in its source, Partonopeus de Blois. Six of the twenty-two French toponyms in the version of Partonopeus drawn upon by Partonope appear at least once in the English text in a different form. At first sight these divergences seem either to be insignificant substitutions or else to arise from common scribal errors. Closer consideration suggests, however, that they are in at least some cases intentional. The principal effect of these alterations, which has escaped the attention of previous scholars, is to shift the location of the Somegur episode from the Vexin to Ponthieu. Given the probable dating of Partonope to the second quarter of the fifteenth century, this relocation may have been designed to avoid a transfer to the Lancastrians of the implicit criticism in Partonopeus of Henry II's possession of Normandy.