Saxons began arriving at the British Isles before the Romans left the area in the 5th century. During the first half of the 5th century, the local Breton rulers invited the Saxons to help them ward off the Picts and Scotis tribes in the north of Britain.
Having succeeded in this, Saxons established a major settlement in England. In time, they expanded their influence and power to overwhelm the local Breton population. This was complemented by new waves of Saxons arriving at the island.
Before soon, Saxons had many kingdoms in England and over subsequent centuries, intermingled with the Germanic Angles to give birth to an Anglo-Saxon identity in England
Different historical traditions regarding the Saxon arrival in England exist. The Saxons began raiding the British shores during Roman reign, so the Roman built many coastal forts to ward off their threat.
The Saxons later settled in the coastal regions as peaceful farmers. Later when the Romans had withdrawn, the Breton population faced the threat of Picts and Scotis in the north of British Isles. They then sought the help of the Saxons in defending them.
This finally brought the Saxons to mainland Britain in a large number. Some historical sources have it that the Breton king Vortigern invited the Saxons to settle in his land in return for this mercenary services. This led to the first establishment of Saxons on the Isle of Thanet.
Although invited by the Bretons to help in their defence, the Saxon settlers in Britain soon rose up against their Breton overlords. The earliest of such uprisings took place in Kent where after a protracted struggle, Saxons successfully ended Breton influence and power.
By the middle of the 5th century, the Saxon rulers were asserting a definite control in southern regions of Britain. In subsequent portions of the century and during the next, many more waves of Saxon populations arrived in England.
This led to the establishment of several Saxon kingdoms. These included the Kingdom of East Saxons or Essex, the Kingdom of Middle Saxons or Middlesex, the Kingdom of South Saxons or Sussex and the Kingdom of West Saxons or Wessex.
During the early phase of Germanic conquest of Britain, Saxons settled a number of kingdoms in southern regions of Britain. Later, the Germanic Angles also launched wave after wave of emigration to Britain during the 6th century, establishing three of their own kingdoms.
Although the Angles established their kingdoms more to the north to avoid confrontation with the Saxons, different kingdoms were soon pitted against each other, not necessarily along tribal but dynastic lines. In time, individual kingdoms began having greater hegemony over others.
In time, this led to intermingling between Angles and Saxons and a sort of common culture and identity. Christianity also played a major role in the crafting of such an identity. The Saxons in Kent and Wessex converted from paganism to Christianity in the 7th century.
This was followed by Essex and Sussex in the same century. As Angle kingdoms to the north and east were also converting, this led to the creation of a unified Anglo-Saxon identity which defined England from 7th century onwards.