Cadwallon ap Einion (c. 460-534; reigned from c. 500), usually known as Cadwallon Lawhir ('Long Hand') and also called Cadwallon I by some historians, was a king of Gwynedd.
According to tradition, Cadwallon ruled during, or shortly after, the Battle of Mons Badonicus, and King Arthur's victory over the Saxons (in either the early 490s or the mid 510s). Cadwallon's name is not connected with the legendary battle, but he may have benefitted from the period of relative peace and prosperity throughout Britain that it procured. The most momentous military achievement of Cadwallon's reign was the final expulsion of Irish settlers on Anglesey, and the re-absorption of that island, which later became the cultural and political base of the kingdom, into Gwynedd.
Cadwallon's epithet, Lawhir, may possibly refer to him having longer than usual arms or might also be a metaphor, referring to the extent of his authority. The late medieval poet Iolo Goch claims that he could "reach a stone from the ground to kill a raven, without bending his back, because his arm was as long as his side to the ground."
According to Gildas, Cadwallon's son, Maelgwn Gwynedd, murdered his uncle to ascend to the throne, which suggests that someone other than Cadwallon himself inherited the kingdom upon Einion's death. No clear evidence exists as to who this "lost king" might be (assuming, of course, that Gildas's account is reliable), but some have suggested the name of Owain Ddantgwyn as the unfortunate heir/victim.
| Preceded by Einion Yrth |
Kings of Gwynedd | Succeeded by Maelgwn Gwynedd |