This book offers important new insights into the history and culture of the Gaelic-speaking world from the mid-fifteenth century through to the reign of James VI and I. Throughout this period, the reach of the English and Scottish crowns within these western regions was limited. The initiative lay with local communities and royal power was contingent upon negotiating with well-established and largely autonomous aristocratic lineages. Moreover, events within this western world could exert a powerful, often unpredictable, influence upon the affairs of the wider archipelago. Using a series of case studies, this collection examines the evolving relationship between Ireland and Scotland in rich detail. It demonstrates how this world interacted with the encroaching English and Scottish states and underlines the importance of paying closer attention to this neglected area of Irish and British history.