This volume offers a range of synchronic and diachronic case studies in comparative Germanic and Romance morphosyntax. These two language families, spoken by over a billion people today, have played a central role in linguistic research, but many significant questions remain about the relationship between them. Following an introduction that sets out the methodological, empirical, and theoretical background to the book, the volume is divided into three parts that deal with the morphosyntax of subjects and the inflectional layer; inversion, discourse pragmatics, and the left periphery; and continuity and variation beyond the clause. The contributors adopt a diverse range of approaches, making use of the latest digitized corpora and presenting a mixture of well-known and under-studied data from standard and non-standard Germanic and Romance languages. Many of the chapters challenge received wisdom about the relationship between these two important language families. The volume will be an indispensable resource for researchers and students in the fields of Germanic and Romance linguistics, historical and comparative linguistics, and morphosyntax.