The history of the tenth century and the first half of the eleventh consists entirely of the continued contest between the West Saxons and the Scandinavians. It falls naturally into three periods. The first is that of the English reaction, when the West Saxon kings, Eadward and Æthelstan, gradually reconquered the Danish North by inches at a time. The second is that of the Augustan age, when Dunstan and Eadgar held together the whole of Britain for a while in the hands of a single West Saxon over-lord. The third is that of the decadence, when, under Æthelred, the ill-welded empire fell asunder, and the Danish kings, Cnut, Harold, and Harthacnut, ruled over all England, including even the unconquered Wessex of Ælfred himself.
At Ælfred'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 Æthelred, who had married Ælfred's daughter Æthelflæd. The departure of the Danish host, led by Hæsten, 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, Æthelred the Mercian died, and Eadward at once incorporated London and Oxford with his own dominions, leaving his sister Æthelflæd only the northern half of her husband's principality. Thenceforth Æthelflæd, "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, Æthelflæd 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. Next, he turned on Stamford, the Danish capital of the Fens, and on Nottingham, the stronghold of the Southumbrian host. In both towns he erected burhs. These successes once more placed the West Saxon king in the foremost position amongst the many rulers of Britain. The smaller principalities, unable to hold their own against the Scandinavians, began spontaneously to rally round Eadward as their leader and suzerain. In the same year with the conquest of Stamford, "the kings of the North Welsh, Howel, and Cledauc, and Jeothwel, and all the North Welsh kin, sought him for lord." In 923, Eadward pushed further northward, and sent a Mercian host to conquer "Manchester in Northumbria," and fortify and man it. A line of twenty fortresses now girdled the English frontier, from Colchester, through Bedford and Nottingham, to Manchester and Chester. Next year, Eadward himself, now immediate king of all England south of Humber, attacked the last remaining Danish kingdom, Northumbria, throwing a bridge across the Trent at Nottingham, and marching against Bakewell in Peakland, where again he built a burh. The new tactics were too fine for the rough and ready Danish leaders. Before Eadward reached York, the entire North submitted without a blow. "The king of Scots, and all the Scottish kin, and Ragnald [Danish king of York], and the sons of Eadulf [English kings of Bamborough], and all who dwell in Northumbria, as well English as Danes and Northmen and others, and also the king of the Strathclyde Welsh and all the Strathclyde Welsh, sought him for father and for lord." This was in 924. Next year, Eadward "rex invictus" died, over-lord of all Britain from sea to sea, while the whole country south of the Humber, save only Wales and Cornwall, was now practically united into a single kingdom of England.
But the seeming submission of the North was fallacious. The Danes had reintroduced into Britain a fresh mass of incoherent barbarism, which could not thus readily coalesce. The Scandinavian leaven in the population had put back the shadow on the dial of England some three centuries. Æthelstan, Eadward's son, found himself obliged to give his sister in marriage to Sihtric or Sigtrig, Danish king of the Yorkshire Northumbrians, which probably marks a recognition of his vassal's equality. Soon after, however, Sihtric died, and Æthelstan made himself first king of all England by adding Northumbria to his own immediate dominions. Then "he bowed to himself all the kings who were in this island; first, Howel, king of the West Welsh; and Constantine, king of Scots; and Owen, king of Gwent [South Wales]; and Ealdred, son of Ealdulf of Bamborough; and with pledge and with oaths sware they peace, and forsook every kind of heathendom." In the West, he drove the Welsh from Exeter, which they had till then occupied in common with the English, and fixed their boundary at the Tamar. But once more the pretended vassals rebelled. Constantine, king of Scots, threw off his allegiance, and Æthelstan thereupon "went into Scotland, both with a land host and a ship host, and harried a mickle deal of it." In 937, the feudatories made a final and united effort to throw off the West Saxon yoke. The Scots, the Strathclyde Welsh, the people of Wales and Cornwall, the lords of Bamborough, and the Danes throughout the North and East, all rose together in a great league against their over-lord. Anlaf, king of the Dublin Danes, came over from Ireland to aid them, with a large body of wickings. The confederates met the West Saxon fyrd or levy at an unknown spot named Brunanburh, where Æthelstan overthrew them in a crushing defeat, which forms the subject of a fine war-song, inserted in full in the English Chronicle. Three years later Æthelstan died, as his father had died before him, undisputed over-lord of all Britain, and immediate king of the whole Teutonic portion.
Yet once more the feeble unity of the country broke hopelessly asunder. Eadmund, who succeeded his brother, found the Danes of the North and the Midlands again insubordinate. The year after his accession "the Northumbrians belied their oath, and chose Anlaf of Ireland for king." The Five Burgs went too, and the old boundary of Watling Street was once more made the frontier of the Danish possessions. In 944, however, Eadmund subdued all Northumbria, and expelled its Danish kings. His recovery of the Five Burgs, and the joy of the Christian English inhabitants, are vividly set forth in a fragmentary ballad embedded in the Chronicle. The next year he harried Strathclyde or Cumberland, the Welsh kingdom between Clyde and Morecambe, and handed it over to Malcolm, king of Scots, as a pledge of his fidelity. At Eadmund's death in 946—when he was stabbed in his royal hall by an outlaw—his kingdom fell to his brother Eadred. Two years later Northumbria again revolted, and chose Eric for its king. Eadred harried and burnt the province, which he then handed over to an earl of his own creation, one of the Bamborough family. The king himself died in 955, and was succeeded by his nephew Eadwig. But Northumbria and Mercia revolted once more, and chose Eadwig's brother, Eadgar, instead of their own Danish princes. Eadwig died in 958, and Eadgar then became king of all three provinces; thus finally uniting the whole of Teutonic England into one kingdom.
Eadgar's reign forms the climax of the West Saxon power. It was, in fact, the only period when England can be said to have enjoyed any national unity under the Anglo-Saxon dynasties. The strong hand of a priest gave peace for some years to the ill-organised mass. Dunstan was probably the first Englishman who seriously deserves the name of statesman. He was born in the half-Celtic region of Somerset, beside the great abbey of Glastonbury, which held the bones of Arthur, and a good deal of the imaginative Celtic temper ran probably with the blood in his veins. But he was above all the representative of the Roman civilisation in the barbarised, half-Danish England of the tenth century. He was a musician, a painter, a reader, and a scholar, in a world of fierce warriors and ignorant nobles. Eadmund made him abbot of Glastonbury. Eadgar appointed him first bishop of London, and then, on Eadwig's death, Archbishop of Canterbury. It was Dunstan who really ruled England throughout the remainder of his life. Essentially an organiser and administrator, he was able to weld the unwieldy empire into a rough unity, which lasted as long as its author lived, and no longer. He appeased the discontent of Northumbria and the Five Burgs by permitting them a certain amount of local independence, with the enjoyment of their own laws and their own lawmen. He kept a fleet of boats cruising in the Irish Sea to check the Danish hosts at Dublin and Waterford. He put forward a code, known as the laws of Eadgar, for the better government of Wessex and the South. He made the over-lordship of the West Saxons over their British vassals more real than it had ever been before; and a tale, preserved by Florence, tells us that eight tributary kings rowed Eadgar in his royal barge on the Dee, in token of their complete subjection. Internally, Dunstan revived the declining spirit of monasticism, which had died down during the long struggle with the Danes, and attempted to reintroduce some tinge of southern civilisation into the barbarised and half-paganised country in which he lived. Wherever it was possible, he "drove out the priests, and set monks," and he endeavoured to make the monasteries, which had degenerated during the long war into mere landowning communities, regain once more their old position as centres of culture and learning. During his own time his efforts were successful, and even after his death the movement which he had begun continued in this direction to make itself felt, though in a feebler and less intelligent form.
One act of Dunstan's policy, however, had far-reaching results, of a kind which he himself could never have anticipated. He handed over all Northumbria beyond the Tweed—the region now known as the Lothians—as a fief to Kenneth, king of Scots. This accession of territory wholly changed the character of the Scottish kingdom, and largely promoted the Teutonisation of the Celtic North. The Scottish princes now took up their residence in the English town of Edinburgh, and learned to speak the English language as their mother-tongue. Already Eadmund had made over Strathclyde or Cumberland to Malcolm; and thus the dominions of the Scottish kings extended over the whole of the country now known as Scotland, save only the Scandinavian jarldoms of Caithness, Sutherland, and the Isles. Strathclyde rapidly adopted the tongue of its masters, and grew as English in language (though not in blood) as the Lothians themselves. Fife, in turn, was quickly Anglicised, as was also the whole region south of the Highland line. Thus a new and powerful kingdom arose in the North; and at the same time the cession of an English district to the Scottish kings had the curious result of thoroughly Anglicising two large and important Celtic regions, which had hitherto resisted every effort of the Northumbrian or West Saxon over-lords. There is no reason to believe, however, that this introduction of the English tongue and English manners was connected with any considerable immigration of Teutonic settlers into the Anglicised tracts. The population of Ayrshire, of Fife, of Perthshire, and of Aberdeen, still shows every sign of Celtic descent, alike in physique, in temperament, and in habit of thought. The change was, in all probability, exactly analogous to that which we ourselves have seen taking place in Wales, in Ireland, and in the Celtic north of Scotland at the present day.
 See chapter xx.
 It is impossible to avoid noticing the increased importance of semi-Celtic Britain under Dunstan's administration. He was himself at first an abbot of the old West Welsh monastery of Glastonbury: he promoted West countrymen to the principal posts in the kingdom: and he had Eadgar hallowed king at the ancient West Welsh royal city of Bath, married to a Devonshire lady, and buried at Glastonbury. Indeed, that monastery was under Dunstan what Westminster was under the later kings. Florence uses the strange expression that Eadgar was chosen "by the Anglo-Britons:" and the meeting with the Welsh and Scotch princes in the semi-Welsh town of Chester conveys a like implication.