King of the Britons

The title King of the Britons (Latin Rex Britannorum) was used (often retrospectively) to refer to the most powerful ruler among the Celtic Britons, both before and after the period of Roman Britain up until the Norman conquest of England. The Britons were the Brittonic-speaking peoples of what is now England, Wales, Cumbria and the Hen Ogledd in southern Scotland, whose ethnic identity is today maintained by the Welsh, Cornish and Bretons.

The same title was also used to refer to some of the rulers of Brittany in the ninth century, but there it is best translated as King of the Bretons. This page concerns only rulers in Britain (with the exception of Riothamus, who may have ruled both in Britain and Continental Europe.)

At least twenty kings were referred to as "King of the Britons", while others were given related titles or descriptions. The table below also contains the paramount native Welsh rulers in the Norman and Plantagenet periods – by this time only Wales (or parts thereof) remained under Brittonic rule in Britain and the term "Briton[s]" (Brython[iaid], Brutaniaid) was used synonymously with what is now the term for the Welsh people, Cymry. This, and the diminishing power of the Welsh rulers relative to the Kings of England, is reflected in the gradual evolution of the titles by which these rulers were known from "King of the Britons" in the 11th century to "Prince of Wales" in the 13th.

Although the majority of the rulers listed below had their power base in Gwynedd in North Wales, most insular Brittonic areas from the 7th century on are to be found in the list below, from Dumnonia in the West Country, to Strathclyde in southwest Scotland.

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