But though Eadberht might beat back the inroads of the Mercians and even conquer Strathclyde, before the anarchy of his own kingdom he could only fling down his sceptre and seek a refuge in the cloister of Lindisfarne. From the death of Baeda the history of Northumbria became in fact little more than a wild story of lawlessness and bloodshed. King after king was swept away by treason and revolt, the country fell into the hands of its turbulent nobles, its very fields lay waste, and the land was scourged by famine and plague. An anarchy almost as complete fell on Wessex after the recovery of its freedom. Only in Mid-England was there any sign of order and settled rule. The crushing defeat at Burford, though it had brought about revolts which stripped Mercia of all the conquests it had made, was far from having broken the Mercian power. Under the long reign of Offa, which went on from 758 to 796, it rose again to all but its old dominion. Since the dissolution of the temporary alliance which Penda formed with the Welsh King Cadwallon the war with the Britons in the west had been the one great hindrance to the progress of Mercia. But under Offa Mercia braced herself to the completion of her British conquests. Pushing after 779 over the Severn, and carrying his ravages into the heart of Wales, Offa drove the King of Powys from his capital, which changed its old name of Pengwern for the significant English title of the Town in the Scrub or Bush, Scrobbesbyryg, Shrewsbury. Experience however had taught the Mercians the worthlessness of raids like these and Offa resolved to create a military border by planting a settlement of Englishmen between the Severn, which had till then served as the western boundary of the English race, and the huge "Offa's Dyke" which he drew from the mouth of Wye to that of Dee. Here, as in the later conquests of the West-Saxons, the old plan of extermination was definitely abandoned and the Welsh who chose to remain dwelled undisturbed among their English conquerors. From these conquests over the Britons Offa turned to build up again the realm which had been shattered at Burford. But his progress was slow. A reconquest of Kent in 775 woke anew the jealousy of the West-Saxons; and though Offa defeated their army at Bensington in 779 the victory was followed by several years of inaction. It was not till Wessex was again weakened by fresh anarchy that he was able in 794 to seize East-Anglia and restore his realm to its old bounds under Wulfhere. Further he could not go. A Kentish revolt occupied him till his death in 796, and his successor Cenwulf did little but preserve the realm he bequeathed him. At the close of the eighth century the drift of the English peoples towards a national unity was in fact utterly arrested. The work of Northumbria had been foiled by the resistance of Mercia; the effort of Mercia had broken down before the resistance of Wessex. A threefold division seemed