Aethelred's reign of nearly thirty-eight years was the longest of any Anglo-Saxon ruler. If he had died in AD 1000, history would have remembered him more kindly'Few monarchs of the Middle Ages have had a worse popular reputation than Aethelred II, 'the Unready', remembered as the king who lost England to Viking invaders. But, as Richard Abels shows, the failure to defend his realm was not entirely his alone. Aethelred was in many ways an innovative ruler but one whose challenges - a divided court, a fragile nascent kingdom, a voracious, hydra-headed enemy - were ultimately too great to overcome.