As long as Ecgbert lived he kept the Danes away from his kingdom of Wessex, dealing them heavy blows whenever they dared to march inland. The greatest of these victories was one gained at Hengistesdun (Hingston Down), near Plymouth, over the combined forces of the Danes and the revolted Welsh of Cornwall (835). But though he was able to protect his own realm, Ecgbert was unable to care for his Mercian and Northumbrian vassals; they were too far off, and his authority over them was too weak. So northern England was already suffering fearfully from the Viking raids even before Ecgbert died. His son Aethelwulf, who succeeded him as king of Wessex, was a pious easy-going man, destitute of his father's strength and ability. If the Mercians and Northumbrians had not been so desperately afflicted at the moment by the ravages of the Vikings, they would have undoubtedly taken the opportunity to throw off the yoke of the Wessex kings. But their troubles made them cautious of adding civil war to foreign invasion, and so Aethelwulf was allowed to keep his father's nominal suzerainty over the whole of England. More than once he led a West-Saxon army up to aid the Mercians, but he could not be everywhere at the same time, and while he was protecting one point, the Danes would slip round by sea and attack another. Wessex itself was no longer secure from their incursions, and the chronicles record several disastrous raids carried out on its coast. All through King Aethelwulf's reign (836-858) the state of England was growing progressively worse. Commerce was at a standstill, many of the larger towns had been burnt by the Danes, the greatest of the monasteries had been destroyed, and their monks slain or scattered; with them perished the wealth and the learning which had made the English Church the pride of Western Christendom. The land was beginning to sink back into poverty and barbarism, and there seemed to be no hope left to the English, for the Viking armies grew larger and bolder every year. [Sidenote: =The Danes threaten permanent occupation.=] After a time the invaders began to aim at something more than transitory raids; they took to staying over the winter in England, instead of returning to Norway or Denmark. Fortifying themselves in strong posts like the isles of Thanet or Sheppey, they defied King Aethelwulf to dislodge them. In a very short time it was evident that they would think of permanently occupying Britain, just as the Saxons and Angles had done three centuries back. Aethelwulf, in great distress of mind, made a pilgrimage to Rome, and obtained the Pope's blessing for his efforts. But he fared none the better for that. It was equally in vain that he tried to concert measures for common defence with his neighbour across the Channel, King Charles the Bald, whose daughter Judith he took to wife. The Frankish king was even more vexed by the pirates than Aethelwulf himself, and no help was got from him.