The multilingual context of medieval Britain has been a focus of historical linguistic scholarship for some time, but Middle English has often been examined in isolation. This book analyzes a large dataset of English vocabulary from the late Middle Ages, a time when the language was gaining new importance, with attention paid to parallel lexical developments in French and Latin. It explores lexical and semantic innovations and losses, and its findings challenge the notion that native and borrowed words were in competition during the period. The book presents a new picture of ongoing bilingualism in the late medieval period and a growth in vocabulary that heralded the beginnings of standardization in English.