Original: The Late pre-Roman Iron Age ( LPRIA ) The last centuries before the Roman invasion saw an influx of refugees from Gaul ( modern day France and Belgium ) known as the Belgae , who were displaced as the Roman Empire expanded around 50 BC .
Simplified: Late pre-Roman Iron Age ( LPRIA ) The last centuries before the Roman invasion saw refugees from Gaul ( modern day France and Belgium ) known as the Belgae , who were displaced as the Roman Empire expanded .