Very early in 867 the ‘Great Army’ swarmed out of East Anglia and passed through Eastern Mercia into Northumbria, which was torn between two claimants to the throne--Osbeorht and Ælla. The Northmen poured over the Humber and captured and sacked York, despite the fact that it was fortified--perhaps the walls of the Roman _castra_ had been patched up. Ælla and Osbeorht thereupon, with surprising patriotism, came to terms and advanced together to recover York. The Northmen were driven back and forced to shut themselves up in the city, and the Northumbrians, impetuously pursuing, became involved in furious street-fighting and met with hideous disaster. Both kings were slain; the flower of the army perished in the streets and during the Viking pursuit; only a remnant escaped. This annihilating defeat resulted in the destruction of Northumbria. For some years Deira remained in a miserable condition, in the power of the Northmen but not regularly ruled by them. North of the Tyne, for about ten years, some obscure princes called themselves kings at Bamborough. Emboldened by this success, the greatest that any Viking host had hitherto gained, the ‘Great Army’ next year, under Ingvar and Hubba, sons of Ragnar Lodbrog, invaded Mercia from Deira and pushed up the Trent. King Aethelred of Wessex marched to the relief of his nominal vassal, Burhred of Mercia, and the two kings confronted the Danes before they had penetrated beyond Nottingham. It was the first positive sign of that hearty co-operation between the states in which lay the only hope of salvation; but on this occasion it was not very successful. The Northmen held out stoutly in Nottingham, and finally in the autumn a truce was concluded by which they agreed to leave Mercia in the spring if they were permitted to winter there without molestation. Whether they received a subsidy is unknown; it is at least possible. During 869 the ‘Army’ streamed back to York, and it was now, perhaps, that they began to think of settling. But their restless and predatory instincts could not die down quickly, and in 870 the bulk of the host set forth again, ‘rode over Mercia into East Anglia, and made their winter quarters at Thetford.’ The great monasteries of the Fens, Peterborough, Ely, Crowland, and Bardney, went up in flames, and Eadmund of East Anglia, taken prisoner after a vain attempt at resistance, was murdered in cold blood. Though there is no authority earlier than Abbo (_circa_ 980), the story is probably true, for shortly afterwards one finds his memory honoured, and churches raised to him by the very men who had murdered him, which could hardly have happened unless they had been deeply impressed by his heroic end. All East Anglia and Essex were soon in Danish hands, and the ‘Great Army’ prepared to advance against Wessex.