St Deiniol (feast day Monday) seems to have been the first Bishop of Bangor in Gwynedd, North Wales. The present Bangor Cathedral (now Anglican) is dedicated to him, and is said to be on the site where his monastery stood, possibly the oldest cathedral site in Britain.

Deiniol was from an old family who lost their land in the North of England but were given land by the King of Powys in Wales. One member joined the Celtic religious life and founded the monastery at a different Bangor, on the river Dee, now better known for horse racing!

Deiniol is said to have studied under St Cadoc at Llancarfan, not far from Cardiff and site of the famous rediscovered frescoes. He also spent part of his early life as a hermit in Pembrokeshire, but was soon called to be a bishop. He soon left Powys for Gwynedd where he founded the monastery of Bangor which was later raised to be the official seat of a bishop, whose diocese covered the principality of Gwynedd. Deiniol would spend the remainder of his days there as Abbot and Bishop.

He attended the famous Synod of Llanddewi Brefi in Carmarthenshire in c. 545 with St David, and was apparently consecrated Bishop by him. It is said he died in 584 and was buried on Bardsey Island the so-called Island of the Saints off the Llyn peninsula. St Deiniol was venerated across North Wales and is also venerated in Britanny as Saint Denoual. In English and Latin his name is sometimes rendered as Daniel.

Prime Minister Gladstone dedicated to him St Deiniol’s Library, a residential library in Hawarden, Flintshire for arts students, in 1896, and is buried at St Deiniol’s Church there. Rather more prosaically, Deiniol’s name, rather like St David in Cardiff, has also been given to the Deiniol Centre, a shopping centre in Bangor!