But all this literary activity was only a part of that general upbuilding of Wessex by which Ælfred was preparing for a fresh contest with the stranger. He knew that the actual winning back of the Danelaw must be a work of the sword, and through these long years of peace he was busy with the creation of such a force as might match that of the northmen. A fleet grew out of the little squadron which Ælfred had been forced to man with Frisian seamen. The national fyrd or levy of all freemen at the King's call was reorganized. It was now divided into two halves, one of which served in the field while the other guarded its own burhs and townships and served to relieve its fellow when the men's forty days of service were ended. A more disciplined military force was provided by subjecting all owners of five hides of land to thegn-service, a step which recognized the change that had now substituted the thegn for the eorl and in which we see the beginning of a feudal system. How effective these measures were was seen when the new resistance they met on the Continent drove the northmen to a fresh attack on Britain. In 893 a large fleet steered for the Andredsweald, while the sea-king Hasting entered the Thames. Ælfred held both at bay through the year till the men of the Danelaw rose at their comrades' call. Wessex stood again front to front with the northmen. But the King's measures had made the realm strong enough to set aside its old policy of defence for one of vigorous attack. His son Eadward and his son-in-law Æthelred, whom he had set as Ealdorman over what remained of Mercia, showed themselves as skilful and active as the King. The aim of the northmen was to rouse again the hostility of the Welsh, but while Ælfred held Exeter against their fleet, Eadward and Æthelred caught their army near the Severn and overthrew it with a vast slaughter at Buttington. The destruction of their camp on the Lea by the united English forces ended the war; in 897 Hasting again withdrew across the Channel, and the Danelaw made peace. It was with the peace he had won still about him that Ælfred died in 901, and warrior as his son Eadward had shown himself, he clung to his father's policy of rest. It was not till 910 that a fresh rising of the northmen forced Ælfred's children to gird themselves to the conquest of the Danelaw.
Eadward the Elder
While Eadward bridled East-Anglia his sister Æthelflæd, in whose hands Æthelred's death left English Mercia, attacked the "Five Boroughs," a rude confederacy which had taken the place of the older Mercian kingdom. Derby represented the original Mercia on the upper Trent, Lincoln the Lindiswaras, Leicester the Middle-English, Stamford the province of the Gyrwas, Nottingham probably that of the Southumbrians. Each of these "Five Boroughs" seems to have been ruled by its earl with his separate "host"; within each twelve "lawmen" administered Danish law, while a common "Thing" may have existed for the whole district. In her attack on this powerful league Æthelflæd abandoned the older strategy of battle and raid for that of siege and fortress-building. Advancing along the line of Trent, she fortified Tamworth and Stafford on its head-waters; when a rising in Gwent called her back to the Welsh border, her army stormed Brecknock; and its king no sooner fled for shelter to the northmen in whose aid he had risen than Æthelflæd at once closed on Derby. Raids from Middle-England failed to draw the Lady of Mercia from her prey; and Derby was hardly her own when, turning southward, she forced the surrender of Leicester. Nor had the brilliancy of his sister's exploits eclipsed those of the King, for the son of Ælfred was a vigorous and active ruler; he had repulsed a dangerous inroad of the northmen from France, summoned no doubt by the cry of distress from their brethren in England, and had bridled East-Anglia to the south by the erection of forts at Hertford and Witham. On the death of Æthelflæd in 918 he came boldly to the front. Annexing Mercia to Wessex, and thus gathering the whole strength of the kingdom into his single hand, he undertook the systematic reduction of the Danelaw. South of the Middle-English and the Fens lay a tract watered by the Ouse and the Nen--originally the district of a tribe known as the South-English, and now, like the Five Boroughs of the north, grouped round the towns of Bedford, Huntingdon, and Northampton. The reduction of these was followed by that of East-Anglia; the northmen of the Fens submitted with Stamford, the Southumbrians with Nottingham. Eadward's Mercian troops had already seized Manchester; he himself was preparing to complete his conquests, when in 924 the whole of the North suddenly laid itself at his feet. Not merely Northumbria but the Scots and the Britons of Strathclyde "chose him to father and lord."
Æthelstan
The triumph was his last. Eadward died in 925, but the reign of his son Æthelstan, Ælfred's golden-haired grandson whom the King had girded as a child with a sword set in a golden scabbard and a gem-studded belt, proved even more glorious than his own. In spite of its submission the North had still to be won. Dread of the northmen had drawn Scot and Cumbrian to their acknowledgement of Eadward's overlordship, but Æthelstan no sooner incorporated Northumbria with his dominions than dread of Wessex took the place of dread of the Danelaw. The Scot King Constantine organized a league of Scot, Cumbrian, and Welshman with the northmen. The league was broken by Æthelstan's rapid action in 926; the North-Welsh were forced to pay annual tribute, to march in his armies, and to attend his councils; the West-Welsh of Cornwall were reduced to a like vassalage, and finally driven from Exeter, which they had shared till then with its English inhabitants, But eight years later the same league called Æthelstan again to the North; and though Constantine was punished by an army which wasted his kingdom while a fleet ravaged its coasts to Caithness the English army had no sooner withdrawn than Northumbria rose in 937 at the appearance of a fleet of pirates from Ireland under the sea-king Anlaf in the Humber. Scot and Cumbrian fought beside the northmen against the West-Saxon King; but his victory at Brunanburh crushed the confederacy and won peace till his death. His brother Eadmund was but eighteen at his accession in 940, and the North again rose in revolt. The men of the Five Boroughs joined their kinsmen in Northumbria; once Eadmund was driven to a peace which left him king but south