Forthwith he marched an army to Cambridge, and invested the island of Ely on every side. The besieged built a great fortress of turf, collected food, and prepared to resist to the death. William determined to storm the island from Aldreth, between which place and Ely lay half a mile of reedy swamp. Collecting all the peasants of the countryside, he busied them in making a floating bridge, over which his army might pass to the capture of the beleaguered isle. Tradition tells us that Hereward, with his golden locks shorn and his beard shaved, laboured at the task, and that every night before he departed he set fire to the day’s work. At length, however, the bridge was finished, and William’s army began to march across it. The besieged watched the vast array crowd upon the frail bridge. Suddenly they saw it give way, and thousands were hurled into the thick slime, which speedily engulfed them. The first attack had hopelessly failed, and William himself had barely escaped destruction. He was not daunted. With that wonderful perseverance and dogged determination which bore down every obstacle in his path, he built his bridge anew, profiting by his former experience. A huge floating sow protected the Ely end of the bridge, and was pushed forward as the work proceeded. Slowly but surely it grew until the sow was but fifty yards from Hereward’s fortress. A high wooden tower was erected at the farther end of the great work, and on this William planted a witch, who yelled and gibbered foul curses at the English as the Normans advanced. The bridge was speedily covered with armed men. The front of the sow was let down, and gave footing to within a dozen yards of the wall of Hereward’s fort. As the Normans swarmed out with their scaling-ladders, the besieged hurled heavy stones upon them, and shot them down by scores, until the ditch was full of dead bodies. The besiegers planted their ladders on the corpses of the slain, and proceeded to mount them, but only one knight ever entered the fort. Afar off a puff of smoke and a thin wisp of yellow flame were seen. Hereward had fired the reeds. “On came the flame, leaping and crackling, laughing and shrieking like a live fiend. The archers and slingers in the boats cowered before it, and fell, scorched corpses, as it swept on. It reached the causeway, surged up, recoiled from the mass of human beings, then sprang over their heads and passed onwards, girding them with flame. The reeds were burning around them; the timbers of the bridge caught fire; the peat and fagots smouldered beneath their feet. They sprang from the burning footway, and plunged into the fathomless bog, covering their faces and eyes with scorched hands, and then sank in the black, gurgling slime.”