monk and bishop of Utrecht. A Northumbrian who was, like Willibrord, an apostle of Frisia, Wiro was appointed to the see of Utrecht by Boniface c.741, but was not archbishop or metropolitan. It is possible that Wiro had been consecrated at Rome earlier, as his biographer claims. He also joined with Boniface in his letter of correction to Ethelbald, king of Mercia, in 746. The centre of his cult was Odilienberg, near Roermond, where he and his companions Pleghelm and Otger had built a church and monastery. Pepin of Herstall had given them the land for these and had encouraged their diffusion of Christianity in Frisia. Wiro was English and died in Holland, but some writers wrongly made him an Irishman who died in Ireland. In this latter they were followed by the Roman martyrology. Feast: 8 May.
AA.SS. Maii II (1680), 309–20 prints the unreliable Life which is no earlier than 858; L. van der Essen, Étude critique et littéraire sur les Vitae des saints mérovingiens (1907), pp. 105–9; W. Levison, England and the Continent in the Eighth Century (1956), pp. 82–3; I. Snieders, ‘L'influence de l'hagiographie irlandaise’, R.H.E., xxiv (1928), 849–50.