spoken form of non-Classical Latin from which originated the Romance group of languages. Vulgar Latin was primarily the speech of the middle classes in Rome and the Roman provinces; it is derived from Classical Latin but varied across Roman-occupied areas according to the extent of education of the population, communication with Rome, and the original languages of the local populations. As the Roman Empire disintegrated and the Christian Church became the chief unifying force in southern and western Europe, communication and education declined and regional variation in pronunciation and grammar increased until gradually, after about 600, local forms of Vulgar Latin were no longer mutually intelligible and were thereafter to be considered separate Romance languages. As the ancestor of the Romance languages, Vulgar Latin is also sometimes called Proto-Romance, although Proto-Romance most often refers to hypothetical reconstructions of the language ancestral to the modern Romance languages rather than to the Vulgar Latin that is known from documents.