This 6th century saint was founder and abbot of a monastery at Holyhead, Anglesey, on Holy Island in Wales. With his friend St. Seiriol, St. Cybi is regarded as the most important saint from the region. There are numerous dedications to St. Cybi throughout Wales and in Cornwall too - including a well at Llangybi near Gwynedd and a half-ruined beehive cell. St Cybi's well is still used for baptism and healing to this day. The name Holyhead is derived from the Welsh, Caercybi which in Welsh means 'Cybi's fortress.' In the Cornish language, he is known as St. Cubi. Holy Island in Welsh is called Ynys Gybi : St. Cybi's Island.
A dedication at Llangiby on Usk describes him as a Cornish saint who traveled by river and sea and lived as a hermit. He was born in Cornwall
According to an account of his life, written in the 13th century, he made a pilgrimage to Jerusalem early in life where he stayed with St. Hilary. He was the son of a king named Salomon or Seylf. Upon returning from Jerusalem, when Cybi found that his father had died, he refused to be crowned. Later he was made bishop and traveled to Ireland via Meneva, before settling in Anglesey. The Welsh prince Maegwn Gwnedd of Cunedda is said to have given him the site for his monastery. He founded numerous churches, among them are churches at Llangybi-ar-Wysg between Usk and Caerleon in Monmouthshire, and Llanddyfrwyr-yn-Edeligion.
The remains on Anglesley are quite unusual, being a Christian church built within the enclosure of a Roman fort, probably a coast guard station. It is one of very few such three-sided Roman fortresses in Europe, the fourth side consisting of the sea itself. The area is replete with pre-historic ruins, among them are the famous 'standing stones' erected by ancient Welshmen.
Romanized Christian Celts were found throughout the region, centuries ago, and left a considerable Christian toponymy to the region. For example, Rhyd-y-Saint railway station, means Ford of the Saints in English. It was named so in honor of both St. Cybi and St. Seiriol who are said to have met there.
Holyhead remains a busy port where ferries and other boats sail for Ireland. St. Cybi is said to have departed from there to visit Ireland, across the Irish Sea. Indeed, it was from Wales that St. Patrick was kidnapped by Irish pirates and taken to Ireland where he would eventually evangelize the natives. Cybi died on November 8, 555 and was buried in 'Capel y Bedd' (the Chapel of the Grave) adjoining his monastery at Holyhead.