Formation and episcopate
Finan was an Irishman who received his monastic training at Iona Abbey in Scotland, the island community founded by Saint Columba that served as the mother house of the Northumbrian mission. From that tradition he came to Lindisfarne, the island monastery and episcopal seat off the Northumbrian coast established by Saint Aidan.
When Aidan died, Finan was chosen to succeed him as the second bishop of Lindisfarne, governing the see from 651 until his own death ten years later. He built a cathedral at Lindisfarne in the Irish fashion, constructed of hewn oak with a thatched roof; the church was later dedicated to Saint Peter by Archbishop Theodore of Tarsus.
Missionary work
Bede records Finan's importance in the conversion of the northern Saxons. He baptized Peada, king of the Middle Angles, and Sigeberht, king of the East Saxons, opening their peoples to the Christian faith. To continue the mission among the East Saxons he consecrated Saint Cedd as their bishop, calling two further bishops to take part in the rite.
Beyond the cathedral at Lindisfarne, Finan is connected with the founding of St. Mary's Priory at the mouth of the River Tyne and with the establishment of Gilling Abbey, founded by Queen Eanflaed. He is also associated with a monastic site on Church Island in Lough Currane, County Kerry, a place still known as St. Finan's Church.
The Easter controversy
Finan held firmly to the customs of Iona, including the older method of calculating the date of Easter that had been kept since the time of Columba. During his episcopate he was challenged by Ronan, an Irish monk who had been trained at Rome and who pressed for the adoption of the Roman Easter. The practical difficulty was acute in Northumbria, where Queen Eanfled and her court might keep Easter on a different day from King Oswiu, so that one part of the court celebrated the feast while the other was still fasting in Lent.
The dispute was not resolved in Finan's lifetime. It fell to his successor Colman, the third Ionan bishop of Lindisfarne, to defend the Ionan position at the Synod of Whitby in 664, which decided in favor of the Roman reckoning.
