(flourished c.820)Irish monk, teacher, astronomer and poet. He addressed a letter to Charlemagne explaining an eclipse of the sun in which he displays a knowledge of astronomy far beyond his time. In 815 he was appointed master of the imperial school at Pavia, and several years later he appeared against Claudius, Bishop of Turin, in a work defending the veneration of images. A number of poems are ascribed to him. He is supposed to have died at the monastery of Bobbio, to which he bequeathed his books.