During the first millennium AD a large part of northern Britain evolved into the country we know today as Scotland. This was an era of transition which saw the end of prehistory and the beginning of the Middle Ages. It was an age of wars and alliances, but also a time of trade and settlement. It saw the native Celtic peoples deal with Roman invasions, Viking raids and the predatory ambitions of Anglo-Saxon kings. The upheavals brought social and political changes that are still present in the languages, laws and landscape of modern Scotland. The period also witnessed the arrival of Christianity, the decline of pagan beliefs and the rise of a new religious elite. By c.900, the most significant change was well underway. Led by a dynasty of Gaelic-speaking kings, the Picts and Scots were merging to form a single nation. As the millennium ended, Scotland was already taking her place among the great realms of medieval Europe. How the new kingdom arose from the troubled centuries that had gone before is one of the stories told in this book.