As for whether Runcorn was really under Uhtred’s control, this is unlikely.
While some fans believe Uhtred is based on the real-life Uhtred the Bold, this is not believed to be the case.
Uhtred of Bebbanburg is a fictitious character, created by Bernard Cornwell for The Saxon Stories novels.
The real-life Uhtred was ealdorman of Northumbria from 1006 to 1016.
His family had ruled from Bamburgh Castle, which inspired Bebbanburg, on the Northumbrian coast.