Tyfrydog

Saint Tyfrydog (Tyvrydog) was a Christian from north-⁠west Wales in the 5th or 6th century, later venerated as a saint, especially on the island of Anglesey. He is said to have founded the church of Llandyfrydog; nothing of the old building remains, but the present church bears his name, and a standing stone nearby is said to be the remains of a man he punished for stealing a Bible from the church.

Few reliable things are known about his life; neither his birth nor his death dates are recorded. His father is recorded as Arwystli Gloff, and father and son are said to have been part of the Christian community on Bardsey island. Some of his brothers are venerated as saints: Twrnog at Llandyrnog and Tudur at Darowen, and his sister Marchell founded Ystrad Marchell, where an abbey was later built. Gerald of Wales tells that in 1098 the hounds of Earl Hugh of Chester, left overnight in the saint's church, went mad, and the earl died within a month.

His day is 1 January, by the Western calendar (new style). He is honored as a confessor and as a saint of the undivided Church.