‘Translation [translatio] is the exposition of meaning through another language [expositio sententiae per aliam linguam]’, claims Hugutio of Pisa in the Magnae derivationes which he compiled between 1197 and 1201. That sentiment, which is rooted in grammatical theory, makes it abundantly clear that medieval ‘translation’ does not mean merely the production of a replacement text: exposition, exegesis, interpretation (however one wishes to denote hermeneutic process) is involved as well. Hence in a twelfth-century gloss on Priscian interpretatio is defined as the exposition (expositio) of one language through another, and in his Summa super Priscianum Peter Helias describes interpretatio as ‘translatio de una loquela in aliam’. Such theoretical discourse is echoed in one of the most widely disseminated vernacular prefaces of the later Middle Ages, Jean de Meun's introduction to his French Boethius (c. 1300). If he had ‘expounded [expons] the Latin by the French word by word, Jean explains, the book would have been too obscure for laymen’ and clerks of moderate learning would have found it difficult to understand the Latin from the French. Therefore he has opted for a freer form of translation – an activity which, quite clearly, remains inseparable from expositio.

The activities of expositio or interpretatio and translatio were complexly interrelated. This chapter seeks to explore some of those relationships, with reference to late-medieval English, French, German and Spanish literary traditions. It will range from quite pedestrian vernacular renderings of standard glosses along with the texts which they expounded, to exceptionally sophisticated exploitations of the techniques – and the scholarly prestige – of commentary in the valorisation of texts composed anew in the emergent European languages.