The Anglo-Saxons were Germanic barbarians who invaded Britain and took over large parts of the island in the centuries following the withdrawal of the Roman Empire. They were initially less gentrified than other post-Roman barbarian groups such as the Franks or Ostrogoths because they had less contact with Mediterranean civilization. The Anglo-Saxons were originally pagan in religion. The main group, from northwestern Germany and Denmark, was divided into Angles, Saxons, and Jutes. German tribal affiliations were loose and the original invaders included people from other Germanic groups as well. Although some of the early Anglo-Saxon invaders had Celtic-influenced names, such as Cedric, the founder of the house of Wessex, the Anglo-Saxons had a pronounced awareness of them-selves as different from the peoples already inhabiting Britain. The early Anglo-Saxons highly valued courage and skill in battle, as reflected in the most significant surviving Anglo-Saxon poem, Beowulf.