An innovative guide to quantitative, corpus-based research in historical and diachronic linguistics, this book provides an original and thoroughly worked-out methodological framework, which encompasses the entire research process. The authors argue that, although historical linguistics has been successful in using the comparative method, the field lags behind other branches of linguistics with respect to adopting quantitative methods. In a theoretically agnostic way, the book provides a framework for quantitatively assessing models and hypotheses in historical linguistics, based on corpus data. Using case studies, the authors illustrate how research questions in historical linguistics can be answered within a framework of quantitative corpus linguistics. With an eye for the needs of researchers, the book explains and exemplifies the benefits of working with quantitative methods, corpus data, corpus annotation, and the benefits of open and reproducible research. Historical corpora, corpus annotation, and historical language resources are discussed in depth, with the aim of enabling researchers to identify appropriate existing resources, or creating their own. The view of quantitative corpus linguistics advocated here offers a unified account of how they fit into the bigger research picture of historical linguistics research.