In recent years, however, as Columbanus's deeds and legacy have come to be re-examined by historians, the traditional narrative of his career has been challenged and doubts have been raised regarding his actual involvement in missionary work and the extent to which he was driven by purely religious motives or also by a concern for playing an active part in politics and church politics in Francia.Columbanus taught an Irish monastic rule and penitential practices for those repenting of sins, which emphasised private confession to a priest, followed by penances levied by the priest in reparation for the sins.
Columbanus and his companions were received with favour by King Gontram of Burgundy, and soon they made their way to Annegray, where they founded a monastery in an abandoned Roman fortress.
After a brief stop in Britain, most likely on the Scottish coast, they crossed the channel and landed in Brittany in 585.
At Saint-Malo in Brittany, there is a granite cross bearing the saint's name to which people once came to pray for rain in times of drought.
He then moved to Bangor Abbey on the coast of Down, where Saint Comgall was serving as the abbot.
He stayed at Bangor until his fortieth year, Columbanus gathered twelve companions for his journey—Saint Attala, Columbanus the Younger, Cummain, Domgal (Deicolus), Eogain, Eunan, Saint Gall, Gurgano, Libran, Lua, Sigisbert, and Waldoleno—and together they set sail for the continent.
Despite its remote location in the Vosges Mountains, the community became a popular pilgrimage site that attracted so many monastic vocations that two new monasteries had to be formed to accommodate them.