These early chronicles are written in Latin, while from the 12th century, some are composed in Middle Welsh.
The oldest surviving manuscripts of chronicles kept in the National Library of Wales, Aberystwyth date to the 13th century.
Accounts in the chronicles pertaining to Dark Age Wales of the 5th and 6th century, including early references to King Arthur, Vortigern, Maelgwn Gwynedd and others, may contain semi-legendary or semi-historical material, which however cannot be substantiated as historical with any certainty.
Brut y Brenhinedd is the title given to Middle Welsh versions of Geoffrey of Monmouth's Historia Regum Britanniae.
The Annals of Owain Glyndwr give an account of the Glyndŵr Rising, covering the period of 1400 to 1422.