Own work, map compiled from a variety of sources:  http://www.english-heritage.org.uk/publications/suffolk-rczas-national-mapping-programme-report/nmpfinal02-02-05.pdf (Suffolk coast prior to reclaimation) http://www.devilsdykeproject.org.uk (Devil's Dyke) http://www.earthtools.org (Flegg and the Great Estuary) http://www.antiquemaps.com/uk/mzoom/29159.htm (Fens, pre-drainage) File:EastAnglia.png (elevation above 50m and 100m) http://www.openstreetmap.org/ (coastline and settlements)
The_kingdom_of_East_Anglia_(Early_Saxon_period).svg
The_kingdom_of_East_Anglia_(Early_Saxon_period).svg: Original uploader was Amitchell125 at en.wikipedia
derivative work: Hoodinski (talk)