At AElfred’s death, his dominions comprised the larger Wessex, from Kent to the Cornish border at Exeter, together with the portion of Mercia south-west of Watling Street.  The former kingdom passed into the hands of his son Eadward; the latter was still held by the ealdorman AEthelred, who had married AElfred’s daughter AEthelflaed.  The departure of the Danish host, led by Haesten, left the English time to breathe and to recruit their strength.  Henceforth, for nearly a century, the direct wicking incursions cease, and the war is confined to a long struggle with the Northmen already settled in England.  Four years later, the east Anglian Danes broke the peace and harried Mercia and Wessex; but Eadward overran their lands in return, and the Kentish men, in a separate battle, attacked and slew Eric their king with several of his earls.  In 912, AEthelred the Mercian died, and Eadward at once incorporated London and Oxford with his own dominions, leaving his sister AEthelflaed only the northern half of her husband’s principality.  Thenceforth AEthelflaed, “the Lady of the Mercians,” turned deliberately to the conquest of the North.  She adopted a fresh kind of tactics, which mark again a new departure in the English policy.  Instead of keeping to the old plan of alternate harryings on either side, and precarious tenure of lands from time to time, AEthelflaed began building regular fortresses or burhs all along her north-eastern frontiers, using these afterwards as bases for fresh operations against the enemy.  The spade went hand in hand with the sword:  the English were becoming engineers as well as fighters.  In the year of her husband’s death, the Lady built burhs at Sarrat and Bridgnorth.  The next year “she went with all the Mercians to Tamworth, and built the burh there in early summer; and ere Lammas, that at Stafford.”  In the two succeeding years she set up other strongholds at Eddesbury, Warwick, Cherbury, Wardbury, and Runcorn.  By 917, she found herself strong enough to attack Derby, one of the chief cities in the Danish confederacy of the Five Burgs, which she captured after a hard siege.  Thence she turned on Leicester, which capitulated on her approach, the Danish host going over quietly to her side.  She was in communication with the Danes of York for the surrender of that city, too, when she died suddenly in her royal town of Tamworth, in the year 918.

Meanwhile Eadward had been pushing forward his own boundary in the east, building burhs at Hertford and Witham, and endeavouring to subjugate the Danish league in Bedford, Huntingdon, and Northampton.  In 915, Thurketel, the jarl of Bedford, “sought him for lord,” and Eadward afterwards built a burh there also.  On his sister’s death, he annexed all her territories, and then, in a fierce and long doubtful struggle, reconquered not only Huntingdon and Northampton but East Anglia as well.  The Christian English hailed him as a deliverer.