[2] Fursey's father is stated to be Fintan son of Finlog (though whether of Momonia or of Mag Murthemni, the Bollandist editor finds the sources not in agreement).

From there, around 633, Fursa went through British territory to the Kingdom of East Anglia with a group of followers including Foillan and Ultan and priests named Gobán and Dicuill.

There they were received kindly by King Sigeberht of East Anglia, who gave Fursa the site of a Roman shore-fort at a place called Cnobheresburg, to build a monastery.

This is derived from the Virtutes Fursei,[6] which states that Fursa decided that he would return to visit his brothers, and set out to do so, but then adds that he died on the journey at his estate at Macerias (Mézerolles in Ponthieu), so in fact did not reach them.

He hastened to ransom the captive monks, recovered the relics, put the holy books and objects of veneration on board ship, and departed for Péronne in Frankish Neustria, where his brother Fursa was buried.

[11] Foillan was one of the numerous Irish missionaries who, in the course of the seventh century, evangelised in Neustria, bringing thither the liturgy and sacred vessels, founding prosperous monasteries, and sharing considerably in the propagation of the faith in these countries.

Owing to the friendship which united him with Erchinoald, Mayor of the Palace (who, however, expelled him from Lagny), and with the members of Pepin's family, Foillan played a significant part in Frankish ecclesiastical history, as shown by his share in the direction of Nivelles and by the foundation of the monastery of Fosses-la-Ville.

As late as the twelfth century the veneration in which he was held inspired Philippe de Harvengt, Abbot of Bonne-Esperance, to compose a lengthy biography of the saint.