In this reign the Danish invasions assume a more terrible aspect; and the second period, the transition to which was marked by the wintering in Sheppey, may be considered to have fully begun. During his short reign, Ethelred, who was a brave warrior, was engaged in almost incessant conflict with these savage heathens. The struggle began in 867, when the brothers Ingvar and Hubba, thirsting, according to a not very probable legend, to avenge their father, who had been put to death by Ella, the sub-king of Northumbria, landed in East Anglia, and took York. In the following year they marched upon Mercia. Nottingham fell; but Ethelred and his brother Alfred came to the assistance of the Mercian king, Burhred, and drove the enemy back into Northumberland. This success was, however, only temporary, for, advancing from York in 870, under a leader named Guthrum, they conquered East Anglia, and it became a Danish kingdom. The under-king of East Anglia was named Edmund; he was defeated near Thetford, and taken prisoner. For his refusal to abjure Christianity, the barbarians shot at him with arrows while he was bound to a tree, and at last beheaded him; wherefore Edmund was deservedly honoured as a saint. Over the whole of East Anglia and Mercia hardly a church or monastery was left standing. All were committed to the flames. With East Anglia as a basis of operations, the Danes extended their advance over parts of England which had as yet escaped. In 871 they penetrated into Wessex; but here their task was not so easy. Nine great battles were fought round Reading; some of them being won by the English, some by the Danes. Of these, the most famous was that of Ashdown, in which Alfred bore the brunt of the fray, while his brother was praying for success. At Easter, King Ethelred died, probably from the effects of a wound. His valour and piety gained for him the title of saint.