Map showing England around 910 CE, showing among others the Viking territories under the Danelaw as well as the English kingdoms of Mercia (at this point in time ruled by Aethelred, Lord of the Mercians (r. 881-911 CE) and Wessex.
Based on Wikipedia content that has been reviewed, edited, and republished.
Original image by Philg88. Uploaded by Emma Groeneveld, published on 06 March 2018 under the following license: Creative Commons: Attribution-ShareAlike. This license lets others remix, tweak, and build upon your work even for commercial reasons, as long as they credit you and license their new creations under the identical terms.