Wilhelm Wattenbach, Deutschlands Geschichtsquellen, Band I (Berlin, 1904)
Clement was, then or later, resident at the Frankish court; there is a poem by him addressed to Lothar as emperor (i.e. after 817), from which it appears that Lothar was his pupil; and another poem, by Ermoldus Nigellus, describes Clement as active in the festivities at Ingelheim on the occasion of the baptism of the Danish king Harald in 826.