The Anglo-Saxons were invading Germanic tribes who dominated England from the early AD 500 to the Norman conquest of 1066. The Benedictine monk, Bede, in his Ecclesiastical History of the English People, identified them as the descendants of the Angles, Saxons, and the Jutes.
Small in number, they were nonetheless able to conquer all of Britain in one generation. How? Initially the regions seized were mainly those that had been closely administrated by Rome, regions where traditions of political and military self-help were at their weakest. Many of these former Briton centers, welcomed Germanic invaders, who, after all were more “Briton” than the Romans (John Davis).
Another compelling reason cited by historians is the emergence in Britain of the great plague of the sixth century from Egypt that was particularly devastating to the Britons who had been in close contact with peoples of the Mediterranean. Be that as it may, the emergence of England as a nation did not begin as a result of a quick, decisive victory over the native Britons, but a result of hundreds of years of settlement and growth, more settlement and growth, sometimes peaceful, sometimes not. The native Celts were constantly warring among themselves too, which made the Anglo-Saxon invasion more effective. As Historian Goldwin explained:
Another obvious attribute of an island is freedom from invasion. The
success of the Saxon invaders may be ascribed to the absence of strong
resistance. The policy of Roman conquest, by disarming the natives, had
destroyed their military character, as the policy of British conquest
has done in India, where races which once fought hard against the
invader under their native princes, such as the people of Mysore, are
now wholly unwarlike. Anything like national unity, or power of co-
operation against a foreign enemy, had at the same time been extirpated
by a government which divided that it might command. The Northman [Saxons] in his
turn owed his success partly to the want of unity among the Saxon
principalities, partly and principally to the command of the sea which
the Saxon usually abandoned to him, and which enabled him to choose his
own point of attack, and to baffle the movements of the defenders. When
Alfred built a fleet, the case was changed.
The Anglo-Saxon invasions of England—and there were multiple invasions—were part of a larger European event. As the Roman Empire collapsed, the Angles, Saxons, and Jutes moved westward. First they were merely raiders; then colonists; finally conquerors. Their invasions were made more effective by the extensive Roman road system and English natural river system. In the end, they were able to conquer more of England than the Romans. They went farther north (into Scotland) and farther west (to Wales).
In a few short decades, the Anglo-Saxons dominated Great Britain. King Alfred the Great (849, ruled 871-899) was the most famous Anglo-Saxon kings. He defended Anglo-Saxon England from Viking raids, formulated a code of laws, and fostered a rebirth of religious and scholarly activity.
Two very important events occurred in the next two centuries: the success of Christianity over all other religions and the political unification of England. In 596 Pope Gregory I sent a monk named Augustine to Kent, where pagan King Ethelbert had married Bertha, a Christian princess. Augustine witnessed to King Ethelbert. Soon after, Ethelbert was baptized and Augustine became the first archbishop of Canterbury. The southern kingdoms–called England–became Christian.
In Northumbria (Northern England and Scotland) the Roman Christianity met Celtic Christianity, which had been brought from Ireland to Scotland by Columba. Although not heretical, the Celtic church differed from Rome in the way the monks cut their hair, in its reckoning of the date of Easter, and, most important, in its organization, which emphasized the clans of Ireland rather than the highly centralized Roman Catholic Church.
All these institutions strengthened Anglo-Saxon hegemony over the region. Furthermore Anglo-Saxon rule was forced to consolidate further by Danish and Viking invasions. For the first time, one people ruled all of Great Britain. Even though Anglo-Saxon rule did not last long, The monarchy was in place, never to end except for a short time during the English Civil War.
The first really important king was Egbert. One of the first Egbert’s grandson, Alfred, became king in one of England’s most precarious moments. Alfred were all that stood in the way of a Danish invasion. Alfred was able for a season to keep the Danes from controlling all of England, even though they controlled most of it. This was to change in 1066.