This book provides the first systematic study of sociolinguistic variation in seventeenth-century France. Drawing on a range of case studies, Wendy Ayres-Bennett makes available new data about linguistic variation in this period, showing the wealth and variety of language usage at a time that is considered to be the most 'standardizing' in the history of French. Variation is analysed in terms of the speaker's 'pre-verbal constitution' - such as gender, age and socio-economic status - or by the medium, register or genre used. As well as examining linguistic variation itself, the book also considers the fundamental methodological issues that are central to all socio-historical linguistic accounts, and more importantly, addresses the question of what the appropriate sources are for linguists taking a socio-historical approach. In each chapter, the case studies present a range of phonological, morphological, syntactic and lexical issues, which pose different methodological questions for sociolinguists and historical linguists alike.