The collection of articles presented in this volume addresses a number of general theoretical, methodological and empirical issues in the field of Historical Linguistics, in different levels of analysis and on different themes: (i) phonology, (ii) morphology, (iii) morphosyntax, (iv) syntax, (v) diachronic typology, (vi) semantics and pragmatics, and (vii) language contact, variation and diffusion. The topics discussed, often in a comparative perspective, feature a variety of languages and language families and cover a wide range of research areas. Novel analyses and often new diachronic data -- also from less known and under-investigated languages -- are provided to the debate on the principles, mechanisms, paths and models of language change, as well as the relationship between synchronic variation and diachrony. The volume is of interest to scholars of different persuasions working on all aspects of language change.