This study recounts the history of the British Isles, from the perspective of its defenders, in a narrative which stretches from the Celtic tribes who fought unsuccessfully against Caesar to the great sea-borne defence against the Armada. Drawing on a blend of military, social and diplomatic history, the text covers the panorama of Celtic and Roman history, the Dark Ages, Saxon and Viking invasions, the Norman Conquest and the Plantagenet and Tudor periods. Norman Longmate has been the historical advisor to film and television companies and has also written How We Lived Then, If Britain Had Fallen and The Bombers.