Over the next century, Angles, Saxons, Jutes, and Frisians arrived and established tribal areas and kingdoms. The area of the Roman city was administered as part of the Kingdom of the East Saxons – Essex, although the Saxon settlement of Lundenwic was not within the Roman walls but to the west in Aldwych. It was not until the Viking invasions of England that King Alfred the Great moved the settlement back within the safety of the Roman walls, which gave it the name Lundenburh. The foundations of the river wall, however, were undermined over time and had completely collapsed by the 11th century. Memory of the earlier settlement survived: it is generally identified as the counted among the 28 cities of Britain included in the "History of the Britons" traditionally attributed to Nennius.