William of Poitiers: Carmen adversus Guibertum Antipapam

This short poem in rhymed leonine hexameters is addressed to Wibert (Guibert) of Ravenna, the imperial antipope Clement III, by William, who calls himself ‘the least of the canons of Saint Hilary’, that is of Saint-Hilaire at Poitiers. The poet urges Wibert not to scorn verses written to him but to come to his senses: he who hurls weapons against heaven shows himself mad; he has seized the kingdom of Christ, violated the holy see like a robber, and bears the name Clement wrongly. The poem calls on him to abandon his enterprise, to remember his death, to prostrate himself before the true pope and confess his sins, since forgiveness is still possible.

The poem is a small example of the verse polemic of the investiture conflict, in which partisans of Gregory VII and Urban II attacked the antipope with wordplay and invective. The pun on ‘Clemens’ and ‘demens’ was a favourite. Migne prints it under William of Poitiers, the historian of William the Conqueror, but the identification with the canon of Saint-Hilaire named in the poem is uncertain.