Hero Myths of the British Isles by Thomas Bulfinch

In Hereward the Wake (or "Watchful") is found one of those heroes whose date can be ascertained with a fair amount of exactness and yet in whose story occur mythological elements which seem to belong to all ages. The folklore of primitive races is a great storehouse whence a people can choose tales and heroic deeds to glorify its own national hero, careless that the same tales and deeds have done duty for other peoples and other heroes. Hence it happens that Hereward the Saxon, a patriot hero as real and actual as Nelson or George Washington, whose deeds were recorded in prose and verse within forty years of his death, was even then surrounded by a cloud of romance and mystery, which hid in vagueness his family, his marriage, and even his death.

Briefly it may be stated that Hereward was a native of Lincolnshire, and was in his prime about 1070. In that year he joined a party of Danes who appeared in England, attacked Peterborough and sacked the abbey there, and afterward took refuge in the Isle of Ely. Here he was besieged by William the Conqueror, and was finally forced to yield to the Norman. He thus came to stand for the defeated Saxon race, and his name has been passed down as that of the darling hero of the Saxons. For his splendid defence of Ely they forgave his final surrender to Duke William; they attributed to him all the virtues supposed to be inherent in the freeborn, and all the glorious valor on which the English prided themselves; and, lastly, they surrounded his death with a halo of desperate fighting, and made his last conflict as wonderful as that of Roland at Roncesvalles. If Roland is the ideal of Norman feudal chivalry, Hereward is equally the ideal of Anglo-Saxon sturdy manliness and knighthood.