Einion

King of Gwynedd in the 5th century, and one of the sons of Cunedda. Einion is one of the ancestors of the later rulers of North Wales. He ruled Gwynedd from the kingdom seat in the Llŷn Peninsula. 
Einion travelled with his father to North Wales in the early 450s to expel Irish raiders from the region. After his father's death, Einion inherited control over the newly founded Kingdom of Gwynedd. Aided by his brother Ceredig, ruler of Ceredigion, and his nephew Meirion, ruler of Meirionnydd, Einion built upon his father's successes and further established his family's rule in the region. He was succeeded by two sons: Cadwallon Lawhir and Owain Ddantgwyn. 
Also: Einion Yrth or Einion ap Cunedda