The Anglo-Saxons were not interested in keeping records and so we know little directly about what happened in early Anglo-Saxon times.
With Christianity came monks who could read and write. The monks lived in the newly-built monasteries. They had the time to begin to chart the history of the Anglo-Saxon times.
One of the most famous monks was called the Venerable Bede. He wrote the whole early history of the Anglo-Saxons.
