The Britons, also known as Celtic Britons and Brythons, were indigenous Celtic people who inhabited Great Britain during the Iron Ages into the early Middle Ages. They settled in what is now mainly England, co-exisiting with the Picts that inhabited what is now Scotland.
The Roman invasion of Britain led to numerous wars waged between the Brittonic tribes and the Roman legions. After the Romans conquered the south of England, the northern Britons were pushed north and were eventually segregated with the construction of Hadrian's Wall.
Following the departure of the Romans in the early 5th century, waves of Germanic tribes of Angles, Saxons and Jutes from continental Europe and coasts of the North Sea migrated onto Great Britain. The Britons integrated with these Germanic tribes to form the bulk of the Anglo-Saxon culture in the Middle Ages.
By the 9th century, the Britons remained inhabiting the region of Wales and were later assimilated by King Rhodri ap Merfyn of Gwynedd, an important step in forming the Kingdom of Wales. However, these Britons remained hostile to the Anglo-Saxon Heptarchy of England and Norse settlers from Scandinavia.