Around 814, he moved his monks a few miles away and founded the monastery of Saint-Mihiel on the banks of the river Meuse, in the diocese of Verdun.
Charlemagne employed him to write the letter to Pope Leo III, in which was communicated the decision of the Council of Aachen (809) respecting the adoption of the filioque clause, and sent him to Rome with the commissioners to lay the matter before the pope.
Louis the Pious showed him equal consideration, endowed his monastery, and in 824 appointed him to act with Frothar of Toul as arbitrator between Ismund, abbot of Moyenmoutier Abbey, and his monks.
His published works in prose are: There remain in manuscript a Commentary on the Prophets, and a History of the Monastery of St. Michael (cf.
p. 112) there have been preserved his metrical introductions to his Collections and Commentary on the rule of St. Benedict, of which the first has twenty-nine lines in hexameter, and the second thirty-seven distichs.