Recent years have witnessed a growing interest in the interconnected histories of the pre-modern archipelago. Nevertheless, scholarship has overwhelmingly focused on the expansion of the early modern English (and subsequently British) state as the main methodological framework for understanding these complex interactions. The limitations of such an approach become increasingly apparent when one considers the range of challenges facing both the Tudors and their Stewart counterparts within the western section of the archipelago. At the dawn of the sixteenth century, over a third of the Irish and British Isles was controlled by autonomous Gaelic-speaking lineages. These families could exert a powerful magnetic pull upon the politics of the wider archipelago, yet their ability to do so remains a sub-theme within the historiographies of later medieval and early modern Ireland and Britain. Using a series of case studies, this collection offers important new perspectives on the history and culture of this lost world. Particular emphasis is placed upon Gaelic source material and the chapters investigate a variety of themes and topics including lordship, dynasticism, political culture, resistance, and resilience. The contributions not only demonstrate the vibrancy of Gaelic political life in Ireland and Scotland in the later medieval and early modern periods, they also explore the rich outpouring of the Gaelic literati and underline the enduring nature of Gaelic culture following the eventual Tudor conquest of Ireland.