This Manual provides a concise, fact-based description of the relevant historical contact situations in the Romance language areas. It describes the linguistic phenomena associated with each of these language contacts (e.g., Celtic, Germanic, Slavic) with reference to relevant studies, and places them within a linguistic-historical or sociolinguistic interpretive framework. In the individual chapters, relevant theories and methods (e.g., Vulgar Latin, substrata, superstrata, adstrata) are addressed, and current research trends and new approaches are reflected upon. For a deeper penetration of the topic, the handbook considers the analytical contributions of the following disciplines: etymology, semantics, creolistics, mixed language theory, colonial linguistics, missionary linguistics, individual bilingualism, code-switching, social multilingualism, migration linguistics, cultural studies, religious studies, music history, politics, and law. The handbook is a guide for all scholars and students working in historical linguistics. Its focus is on contact situations in the period of the emergence of Romance languages and their further spread in the world.