Here he invoked the Holy Name, and by its power the idols were miraculously overthrown, and a multitude of the people were converted, including in their number some of the principal inhabitants of Bregentz.
The theological controversy, known as that of the "Three Chapters," was now prevalent in northern Italy.

A letter is still extant which St.
Columbanus addressed to Pope Boniface on this subject, in which, while he uses the privilege of free discussion on questions not defined by the Church, he is remarkably, and perhaps for some inconveniently, explicit as to his belief in papal supremacy.

A brief extract from this important document will show that the faith for which Ireland has suffered, and still suffers so much, was the same in the "early ages" as it is now.

He writes thus to the Holy Father:-- "For we Irish [Scoti] are disciples of St.Peter and St.Paul, and of all the divinely inspired canonical writers, adhering constantly to the evangelical and apostolical doctrine.

Amongst us neither Jew, heretic, nor schismatic can be found; but the Catholic faith, entire and unshaken, precisely as we have received it from you, who are the successors of the holy Apostles.