 Sometime about 886, the "burh" of Southwark was created and the Roman city area reoccupied.It was probably fortified to defend the bridge and hence the reemerging City of London to the north.This defensive role is highlighted by the use of the bridge in 1016 as a defence against King Sweyn and his son King Cnut by Ethelred the Unready and again, in 1066, against Duke William the Conqueror.