At length, however, the Conqueror marched northward, and, advancing upon York, slaughtered all who attempted resistance, and, sword in hand, entered the capital of the north. Feeling that the struggle was hopeless, many of the chief Northumbrians descended the Humber in boats, and sought refuge on Scottish soil, there to watch events; and William, after erecting a strong castle, and appointing William Malet as Governor of York, returned southward. But the aspect of affairs speedily became so alarming, that the king prepared for a second expedition, and reached York at the very time when the citizens and the inhabitants of the country had formed a league, and were besieging the Norman fortress. Attacking them with his wonted energy, William succeeded in killing or dispersing the insurgents, and, determined on extending his sovereignty at least as far as Durham, he entrusted the task of doing so to Robert Comine, whom he by anticipation created earl of the county that was to be subdued. With an army of nine thousand men, twelve hundred of whom were horsemen, Robert Comine ventured on his perilous enterprise. At first all seemed to go prosperously; and he became quite confident when he found himself approaching Durham without having seen the face of a foe. At that point, however, he was met by Eghelwin, Bishop of Durham, who hinted that there was danger in the way. "I advise you," said the bishop, "to be prudent and beware of a surprise." "Who would attack me?" asked Comine, with contempt. "None of you, I imagine, would dare to do so." And with these words the Norman warrior rode into the city and took up his quarters in the bishop's palace, while his troops encamped in the square. Everything, so far, seemed secure; but after nightfall a wonderful change occurred. On every hill a signal-fire was lighted, and armed men, gathering from the banks of the Tyne, assembled in great numbers, and hastened towards Durham. By daybreak they were before the walls, and, forcing the gates, they entered with a mighty rush, and fell ferociously upon the Normans. Dismayed, but not yet despairing, Comine attempted to rally his soldiers in the bishop's palace, erected barricades, and showered arrows from the roofs; but every effort proved vain. The Northumbrians, resolutely pressing on, set fire to the episcopal mansion, and Comine and every man within the walls perished in the flames. After this successful attempt at revolt, the Northumbrians summoned allies to their side. They implored aid from the King of Denmark, and they recalled the Saxons who had exiled themselves to the Scottish frontier. Both responded with alacrity. A Danish fleet, sent by the King of Denmark, under the command of his brother, entered the Humber; and Edward Atheling, Siward Beorn, and Merlesweyn, and Waltheof, son of the great Siward, who had all taken refuge in Scotland, hastened to Durham.