Edward the Elder spent twenty-five laborious years first in repelling and repaying Danish raids, then in setting to work to subdue the raiders. He worked forward into the Danelagh, building _burhs_ as he advanced, to hold down each district that he won. He was helped by his brother-in-law, the Mercian ealdorman Æthelred, and, after the death of that magnate, by his warlike sister Æthelflæd, the ealdorman's widow, who was continued in her husband's place. While Edward, with London as his base, pushed forward into the eastern counties, his sister, starting from Warwick and Stafford, encroached on the Danelagh along the line of the Trent. The last Danish king of East Anglia was slain in battle in 918, and his realm annexed. Æthelflæd won Derby and Leicester, while her brother reduced Stamford and Nottingham. Finally, in 921, not only was the whole land south of the Humber subdued, but the Yorkshire Danes, the Welsh, and even--it is said--the remote Scots of the North, did homage to Edward and became his men. Æthelstan. In 925 Edward was succeeded by his eldest, son Æthelstan, who completed the reduction of the Danelagh by driving out Guthfrith, the Danish king of York, and annexing his realm. But this first conquest of the region beyond Humber had to be repeated over and over again; time after time the Danes rebelled and proclaimed a new king, aided sometimes by bands of their kinsmen from Ireland or Norway, sometimes by the Scots and Strathclyde Welsh. Æthelstan's greatest and best-remembered achievement was his decisive victory in 937 at Brunanburh--an unknown spot, probably by the Solway Firth or the Ribble--over a great confederacy of rebel Danes of Yorkshire, Irish Danes from Dublin, the Scottish king, Constantine, and Eugenius, king of Strathclyde. Yet even after such a triumph Æthelstan had to set up a Danish under-king in Yorkshire, apparently despairing of holding it down as a shire governed by a mere ealdorman. But its overlordship he never lost, and since he also maintained the supremacy which his father had won over the Welsh and Scots, it was not without reason that he called himself on his coins and in his charters _Rex totius Britanniae_. Occasionally he even used the title _Basileus_, as if he claimed a quasi-imperial position. Edmund: Edred.