Editing Deira (section)

=== Brythonic Deira===
Following the [[End of Roman rule in Britain|Roman withdrawal from Britain]] a number of successor kingdoms rose in northern England, reflecting pre-Roman tribal territories. The area between [[the Humber]] and [[River Tees]] known as {{lang|xcb|Deywr}} or {{lang|owl|Deifr}} corresponds to the tribal lands of the [[Parisi (tribe)|Parisi]], bordered to the west and north by the Brythonic kingdoms of [[Elmet]] ({{lang|owl|Elfed}}) and [[Bernicia]] ({{lang|owl|Bryneich}}) respectively, and to the east by the [[North Sea]].

Early Deira may have centred on [[Petuaria]] (modern [[Brough, East Riding of Yorkshire|Brough]]) and archaeological evidence shows that the town was refortified. Petuaria was a great tribal centre for the Parisi, but declined in importance from the mid-fourth century (possibly as the harbour silted up). After this period, [[Derventio Brigantum|Derventio]] (modern [[Malton, North Yorkshire|Malton]]) may have functioned as the region's capital.<ref>{{cite book |last1=B. Sitch & A. Williams |title=Roman Humberside |date=1992 |publisher=Humberside County Council Archaeology Unit}}</ref>

It is not known if Deira was ever an independent Brythonic kingdom, and no British king has been identified with the area from the surviving genealogies, poems or chronicles. However the area was subject to the same fractious inheritance traditions and changing power dynamic (following the Roman withdrawal) that allowed [[Elmet]] and Bernicia to become independent hereditary kingdoms in the early fifth century. In [[Welsh literature]], Deira is part of the {{lang|cy|[[Hen Ogledd]]}} (The Old North) region, which was divided into many related kingdoms after the death of {{lang|cy|[[Coel Hen]]|italic=no}} (Coel the Old).<ref>Morris, p. 54.</ref><ref>Koch 2006, pp. 584–585.</ref>