Fursey was born in the region of modern-day Connacht supposedly the son of Fintan and grandson of Finlog, pagan king of the area. His mother was Gelges, the Christian daughter of Aed-Finn, king of Connacht. He was born probably amongst the Hy-Bruin, and was baptised by St Brendan the Traveller, his father’s uncle, who then ruled a monastery in the Island of Oirbsen, now called Inisquin in Lough Corrib.
Fursey was educated by St Brendan’s monks, and when he became of the proper age he was inducted into the monastery at Inisquin (near Galway), under the Abbot St Meldan, his “soul-friend” (anam-chura), where he devoted himself to religious life. His great sanctity was early discerned, and there is a legend that here, through his prayers, twin children of a chieftain related to King Brendinus were raised from the dead. Fursey then built his own monastery in Claran outside the town of Headford in Co. Galway and he became the patron saint of the Parish of Headford.
Fursey arrived in France in 648. Passing through Ponthieu, in a village near Mézerolles he found grief and lamentation on all sides, for the only son of Duke Haymon, the lord of that area, was dead. At the prayer of Fursey the body was restored. Pursuing his journey to Neustria he cured many infirmities on the way. He converted a robber, who had attacked the monks in a wood near Corbie, and his family through miracles.
His fame preceded him to Péronne, where he was joyfully received by Erchinoald, and through his prayers obtained the reprieve of six criminals. He was offered any site in the king’s dominions for a monastery. He selected Latiniacum (Lagny), close to Chelles and about six miles from Paris, a spot beside the Marne, at that time covered with shady woods and abounding in fruitful vineyards.
Fursey died about 650 at Mézerolles while on a journey. His last illness struck him down in the very village, Mézerolles, where he had restored Duke Haymon’s son to life. From that time forward the village was called Forsheim, which translated as the house of Fursey. His body lay unburied for thirty days pending the dedication of the church, and was during that time visited by pilgrims from all parts, incorrupt and emitting a sweet odour. At the end of that time, it was buried near the altar of the church. Four years later, on February 9, his remains were moved from their earlier location by Saint Eligius, Bishop of Noyon, and Cuthbert, Bishop of Cambrai, to a new chapel specifically built to hold the remains to the east of the main altar. The city would later become a great centre of devotion to him.