Early historic Scotland - from the fifth to the tenth century AD - was home to a variety of diverse peoples and cultures, all competing for land and supremacy. Yet by the eleventh century it had become a single, unified kingdom, known as Alba, under a stable and successful monarchy. How did this happen, and when? At the heart of this mystery lies the extraordinary influence of the Picts and of their neighbours, the Gaels - originally immigrants from Ireland. In this new and revised edition of her acclaimed book, Sally M. Foster establishes the nature of their contribution and, drawing on the latest archaeological evidence and research, highlights a huge number of themes, including the following: the origins of the Picts and Gaels; the significance of the remarkable Pictish symbols and other early historic sculpture; the art of war and the role of kingship in tribal society; settlement, agriculture, industry and trade; religious beliefs and the impact of Christianity; how the Picts and Gaels became Scots.