Skip to main content


Cadwallon (d. 634), king of Gwynedd. With his ally Penda of Mercia, Cadwallon was responsible for the death of Edwin of Northumbria at the battle of Heathfield in 633 and for those of his successors Osric of Deira and Eanfrith of Bernicia the following year. In 634 he was himself defeated and slain by Eanfrith's brother Oswald at the battle of Heavenfield, near Hexham. Not surprisingly Cadwallon gets a consistently bad press in Bede's Ecclesiastical History, especially for his brutal ravaging within Northumbria. In Welsh poetry he is celebrated as a ‘lion of hosts over the Saxons’ and his hostility to Northumbria is explained as a reaction to previous attacks on north Wales by the deceitful Edwin.

Barbara Yorke

Cite this article
Pick a style below, and copy the text for your bibliography.

  • MLA
  • Chicago
  • APA

"Cadwallon." The Oxford Companion to British History. . 23 Feb. 2019 <>.

"Cadwallon." The Oxford Companion to British History. . (February 23, 2019).

"Cadwallon." The Oxford Companion to British History. . Retrieved February 23, 2019 from

Learn more about citation styles

Citation styles gives you the ability to cite reference entries and articles according to common styles from the Modern Language Association (MLA), The Chicago Manual of Style, and the American Psychological Association (APA).

Within the “Cite this article” tool, pick a style to see how all available information looks when formatted according to that style. Then, copy and paste the text into your bibliography or works cited list.

Because each style has its own formatting nuances that evolve over time and not all information is available for every reference entry or article, cannot guarantee each citation it generates. Therefore, it’s best to use citations as a starting point before checking the style against your school or publication’s requirements and the most-recent information available at these sites:

Modern Language Association

The Chicago Manual of Style

American Psychological Association

  • Most online reference entries and articles do not have page numbers. Therefore, that information is unavailable for most content. However, the date of retrieval is often important. Refer to each style’s convention regarding the best way to format page numbers and retrieval dates.
  • In addition to the MLA, Chicago, and APA styles, your school, university, publication, or institution may have its own requirements for citations. Therefore, be sure to refer to those guidelines when editing your bibliography or works cited list.