Saint Finnian of Clonard (Cluain Eraird) is also called Finian, Fionán or Fionnán in Irish; or Vennianus and Vinniaus in its Latinised form. He was born at the end of the 5th century around 470, probably at Idrone, County Carlow. He was baptised by Saint Abban and was placed under the care of Bishop Fortchern of Trim at quite an early age.
Near Idrone he made his first foundations Rossacura, Drumfea, and Kilmaglush. Afterwards he went to Wales and studied the monasticism of David, Cadoc and Gildas. According to the Codex Salmanticensis, he spent 30 years there.
When he returned to Ireland, he travelled the country preaching, teaching and founding churches like for example Skellig Michael eight miles off the coast of County Kerry (the coast in his background) and made foundations at Aghowle (County Wicklow) and Mugna Sulcain.
After he had visited Kildare, he founded Clonard (County Meath), where numerous disciples gathered around him. Clonard’s special characteristic was to unity study with the Welsh form of monastic life. Some of his students were Columcille, Cianneach of Aghaboe, Comgall of Bangor and Ciaran of Clonmacnoise.
When his students left Clonard, they took with them a crozier, a gospel book and a reliquiary, round which they later built there churches and monasteries.
Finnian died of plague on December 12th 549 (some sources say 552). His relics were enshrined at Clonard until their destruction in 887.
His feast day is December 12th.
Source: Oxford Dictionary of Saints