Offa, king of the Mercians (757 – 96), son of Thingfrith the son
of Eanwulf, was first cousin to Æthelbald 4, king of the
Mercians (716 – 757). Offa 7 became king of the Mercians after
driving out Æthelbald 4’s short-lived successor, Beornred 1. By
the end of his reign Offa 7 was the most powerful king in
England and, to varying extents, exercised lordship over Sussex,
Kent, Essex and East Anglia, although it is unlikely that he
exercised any direct lordship over Wessex or Northumbria. His
reign has come to be viewed as a period of significant military
and urban development in the face of Viking depredations. S.
Kelly, ODNB; BEASE, 340 – 1; F. M. Stenton, ‘The supremacy of
the Mercian kings’, Preparatory to ‘Anglo-Saxon England’: being
the collected papers of Frank Merry Stenton, ed. D. M. Stenton
(1970), 48–66; P. Wormald, 'The Age of Offa and Alcuin', in The
Anglo-Saxons ed. J. Campbell (1982), pp 101 – 28; J. Haslam,
‘Market and fortress in England in the reign of Offa’, World
Archaeology 19 (1987), 76 – 9