Einion Frenin

Saint Einion Frenin (Welsh: old , mod. or , "Saint Einion the King"; or Anianus and early 6th century Welsh confessor and saint of the Celtic Church. His feast day was originally given as 9 February, although this had moved to the 10th or 12th by the 16th century or Catholic church in Wales.

Life Saint Einion was a son of Owain Whitetooth (Owain Danwyn) and the brother of Cuneglasus, king of Rhos, and of saints Seiriol and . Part of Gwynedd's Cuneddan dynasty, he seems to have ruled as a local king over the Llŷn Peninsula southwest of Anglesey and possibly over Anglesey itself. He was credited with granting his brother Seiriol the land for his monastery at Penmon on Anglesey He also lured the Breton saint Cadfan from Tywyn to found St Mary's Abbey, the first religious establishment on Bardsey Island. although his relics were claimed by the church at Llanengan. and bears Latin inscriptions reading Æniani Rex Wallie and Rex Walliæ ("Einion, king of Wales"). Miraculous locations nearby include Ffynnon Engan ("Einion's Well") and Ol Troed March Engan ("The Hoofprint of Einion's Horse"), a petrosomatoglyph near Castell Cinan whose collected rainwater was claimed to possess curative powers. Other placenames possibly related to the king are Ogo' Engan ("Einion's Cave"), Bryn Engan ("Einion's Hill"), Caer Engan ("Engan's Camp"), and Croes Engan ("Einion's Cross"), a farm in Denbighshire.

Llandogo in Monmouthshire was also sometimes previously known as Lann Enniaun ("Llanennion") and the bard Hywel Rheinallt composed a cywydd to the "golden-handed" Saint Einion in the late 15th century, recording another (now unknown) church in Gwynedd dedicated to St Einion.