This lecture has to perform a double act, resisting the nationalizing teleology attached to the late fourteenth century that makes French always already about to die, while acknowledging the vigorous growth of English as a written language of culture (though not an official language of the crown) in the later part of the century. Accordingly, it anchors the continuing but shifting multilingualism of the fourteenth century by looking forward from the late thirteenth and early fourteenth centuries before turning to some domains of literature, record, and administration to address changes and continuities in the latter half of the century. As some eloquent modern scholarship has shown, the fluctuations of war and truce between English and French contemporaries entangled them more intensely in their shared French vernacular. English’s expanding domains and the great English-language late medieval literary experimentation and consolidation are neither the outcome of conflict nor evidence of serial monolingualism.