Kingdom of Deira

Deira ( ; Old Welsh/ or ; or ) was an area of Post-Roman Britain, and a later Anglian kingdom. Etymology The name of the kingdom is of Brythonic origin, and is derived from the Proto-Celtic , meaning 'oak' ( in modern Welsh), in which case it would mean 'the people of the Derwent', a derivation also found in the Latin name for Malton, . It is cognate with the modern Irish word; the names for County Londonderry and the city of Derry stem from this word. History Brythonic Deira Following the 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 or corresponds to the tribal lands of the Parisi, bordered to the west and north by the Brythonic kingdoms of Elmet and Bernicia respectively, and to the east by the North Sea.