sentences:  Great Britain's Iron Age inhabitants are known as Britons; they spoke Celtic languages.The Romans conquered most of the island (up to Hadrian's Wall in northern England) and this became the Ancient Roman province of "Britannia".In the course of the 500 years after the Roman Empire fell, the Britons of the south and east of the island were assimilated or displaced by invading Germanic tribes (Angles, Saxons, and Jutes, often referred to collectively as Anglo-Saxons).