With the decline of the Roman Empire in the 3rd and 4th centuries, various Germanic tribes expanded into the Roman lands in the west forming their own Franco-Saxon kingdoms. In the 5th century the Byzantine Empire reasserted itself after internal strife and succeeded in regaining much of the lost land. However, on the marches, the barbarian kingdoms remained a threat.
The most prominent tribes were the Franks and the Saxons giving rise to the name but also included the Lombards and the Visigoths. The Angles ventured northwest, across the sleeve, and established themselves in Britannia. As such they did not include themselves in these kingdoms but instead fought a number of wars with them.