The hidden story of a little-known but transformative period in the formation of England as a nation. The Viking Great Army that swept through England between AD 865 and 878 altered the course of British history. Since the late 8th century, Viking raids on the British Isles had been a regular feature of life, but the winter of 865 saw a fundamental shift that would change the political, economic and social landscape forever. Instead of making quick smash-and-grab summer raids for silver and slaves, Vikings now remained in England for the winter and became immersed in its communities. Some settled permanently, acquiring land and forming a new hybrid Anglo-Scandinavian culture. The Viking army was here to stay. Its presence was a catalyst for new towns and new industries, while transformations in power politics would ultimately see the rise of King Alfred the Great and make Wessex the pre-eminent kingdom of Anglo-Saxon England. Drawing on the most up-to-date discoveries and the latest scientific techniques, the authors' recent research at the Viking Great Army's winter camp at Torksey in Lincolnshire has revolutionized what we know about its size, activities and social makeup, as has the wealth of newly recovered evidence from metal-detectorists. Unfolding like a great detective story, this account traces the movements of the Great Army across the country, piecing together a new picture of Viking Age England in unprecedented detail, from swords, coins, jewelry and the burials of great warriors to the everyday objects that ordinary farmers and craftsmen discarded. It is the definitive story of a vital period in British history.