Brut y Saeson

Brut y Saeson is a Welsh-language chronicle running from the death of Cadwaladr ap Cadwallon in 682 to the reign of Richard II of England. The name means the brut or chronicle of the English.
It is found in three related manuscripts from the late fourteenth or early fifteenth century, two of which are held by the National Library of Wales in Aberystwyth and one of which is at Oxford. The version in Peniarth 19 breaks off in AD 979.
It has been described by Professor Huw Pryce as 'a striking witness to how long-established notions in Wales of the Britons' loss of sovereignty over Britain could sustain an interest in English as well as Welsh history'.