Earldom of The Five Boroughs
Following Danish conquest in 1016, Earl Sired succeeded to the newly created Earldom of the Five Boroughs under King Canute in 1019. By 1035 the Earldom had been subsumed into that of Leofric, Earl of Mercia, and it was to form a formal administrative unit long into the future.
Read more about this topic: Five Boroughs Of The Danelaw