From Bede's writings we find that the Scots from the west and the Picts from the north continually harassed the Britons despite occasional help from Rome, and despite the wall they built across the north of England. In these straits the British invited help from the Angles and Saxons, who soon engaged the northern tribesmen and defeated them. The feebleness of the Britons having become well known among the continental peoples, the Angles, Saxons and Jutes began to steadily swarm across the North Sea in powerful, armed bands. Having for a time assisted the Britons they began to seek excuses for quarrels, and gradually the Britons with brief periods of success were beaten and dispossessed of their lands until they were driven into the western parts of the island. The Angles occupied most of northern England, including the kingdom of Northumbria, of which Yorkshire formed a large part. These fierce Anglo-Saxon people, with an intermixing of Danish blood, a few centuries later were the ancestors of a great part of the present population of the county. Sidonius Apollinaris, a Bishop of Gaul, who wrote in the fifth century, says, "We have not a more cruel and more dangerous enemy than the Saxons: they overcome all who have the courage to oppose them; they surprise all who are so imprudent as not to be prepared for their attack. When they pursue they infallibly overtake; when they are pursued their escape is certain. They despise danger; they are inured to shipwreck; they are eager to purchase booty with the peril of their lives. Tempests, which to others are so dreadful, to them are subjects of joy; the storm is their protection when they are pressed by the enemy, and a cover for their operations when they meditate an attack. Before they quit their own shores, they devote to the altars of their gods the tenth part of the principal captives; and when they are on the point of returning, the lots are cast with an affectation of equity, and the impious vow is fulfilled." Gradually these invaders settled down in Britain, which soon ceased to be called Britain, and assumed the name Angle-land or England. In A.D. 547 Ida founded the kingdom of Northumbria, one of the divisions forming the Saxon Heptarchy, and among the villages and families that owed allegiance to him were those of the neighbourhood of Pickering. The first fortifications by the Anglo-Saxons were known as _buhrs_ or _burgs_. Some of them were no doubt Roman or British camps adapted to their own needs, but generally these earth works were required as the fortified home of some lord and his household, and there can be little doubt that in most instances new entrenchments were made, large enough to afford a refuge for the tenants as well as their flocks and herds.