This chapter presents a comprehensive analysis of the history of preaspiration in the North Germanic languages. Building on a wide range of both traditional and more recent instrumental investigations, it develops an account that puts a theoretically informed model of phonology at the heart of the analysis, in preference to other criteria used in recent work, such as ‘normative’ status. The analysis is set within the wider context of the Germanic language family and its phonological development, in particular the role of moraic quantity. In addition to preaspiration itself, the chapter provides novel accounts of several related phenomena, most notably the lenition of intervocalic stops. It demonstrates that the life-cycle model offers a clear and consistent account of typological variation in patterns of preaspiration across the entire North Germanic family, allowing us to trace its history from a stage preceding the North Germanic protolanguage to the multifarious developments in present-day vernaculars.