It was not till the year 1068 that the Normans succeeded, after a severe contest, in taking Oxford, Warwick, and the old Danish burghs Leicester, Derby, Nottingham, Lincoln, and York. In these places, but especially in Lincoln and York, the Normans were obliged to build strong fortifications, for fear of the people of Scandinavian descent, who abounded both in the towns and in the adjacent rural districts. But what the Normans chiefly apprehended was, attacks from the Danes who, there was good reason to suppose, might come over with their fleets to the assistance of their countrymen in the north of England. Meantime, whilst the remains of the united Anglo-Saxon and Danish-Norwegian armies had withdrawn to the mountains of Northumberland, where they often surprised and killed whole detachments of Norman troops, numerous fugitives and messengers repaired to King Svend in Denmark, to implore him, in the name of his English friends, and in that of freedom, to assist them against William the Conqueror. Svend sent his brother Asbjörn, and his sons Harald and Canute, over with a fleet, who, after a vain attempt to land at Sandwich, entered the Humber, in the year 1069. The Northumbrians, and the rest of the aggrieved inhabitants, both Northmen and Anglo-Saxons, flocked gladly together under the Danish banner. Edgar, who had been chosen king by the Anglo-Saxons, Valthjof (Waltheof), a son of the old Northumbrian jarl Siward, and many other fugitives, joined the Danish host. York was taken, the Normans put to flight, and their fortifications levelled with the ground. In these encounters Waltheof gained great honour for courage and bravery. But the joy of victory was only of short duration. William, who had sworn in his anger to lay all Northumberland waste, knew how to avert by persuasion, cunning, and bribery, the danger that threatened him from Denmark. The Danish fleet went home in the spring; and William retook York, and extended his dominion in Northumberland; where his progress was marked by slaughter, incendiarism, and rapine. The unfortunate inhabitants fled to the forests and morasses; their last place of refuge was the marshes near the Wash. Moved by the cries of complaint which continually reached him from England, the Danish king Svend again sent a number of vessels, which appeared in the Humber in the year 1074. But these were not able to render any effectual assistance. Waltheof, whom William, in order to conciliate the Northumbrians, had appointed Jarl in his father’s earldom, fell under the axe of the executioner on suspicion of being concerned in this naval expedition; and fresh devastations promoted William’s dominion over Northumberland, which was so terribly harassed that large districts were left without houses or human inhabitants.