This chapter explores how to establish a chronology of the development of Latin into the Romance languages using the methodology of historical sociolinguistics, whilst at the same time attempting to model this change in a historically informed way. Certain features of synchronic sociolinguistics can be identified which have a direct bearing on diachronic studies. Indeed, at the beginning of the fifth century, Latin presents a communicative continuum which is not very different from what one would find in other sociolinguistic contexts, ancient and modern. St. Augustine was a Roman from Africa who displayed great learning and prodigious linguistic gifts, but he was unafraid to exploit language, including clashes of register and asperities of style. The chapter also discusses the development of the relationship between writing and speech from late spoken Latin to proto-French, linking the various stages to the stages proposed for the development of speech and communication.

This chapter focuses on the application of modern socio-linguistic advances to the Carolingian period. From the socio-linguistic point of view, the transition from different kinds of spoken Latin to the Romance languages, and the corresponding wreck of general Latin communication, led, from the 750s onwards, to the establishment of a situation of diglossia. The end of the Merovingian centuries and the whole of the Carolingian period in the linguistic and cultural history of Europe can be described in a way which, however complex its elements, reveals a creative development, much less confused than appeared at first sight; the ills and the disorders which the language of the Merovingian charters appears, time and time again, to display are the indirect sign of an intense linguistic activity, from which would emerge the new and unforeseen perfection of the Romance dialects, fruit of a process by which final order was born of apparent chaos.