Desiderius of Rennes

Saint Desiderius of Rennes (in French Didier or Dizier) was a bishop who lived in the 7th century. He was born at Rennes in Brittany, where he studied the Holy Scriptures and became bishop. He was killed by robbers near the place that now bears his name, Saint-⁠Dizier-⁠l'Évêque, in the Territoire de Belfort in eastern France.

He set out on pilgrimage to Rome with two companions, the deacon Regenfrid and Willibert. On the way back he passed through Alemannia and came, in 672 or 673, south of the Vosges, where the local Christian community received him in an oratory. After preaching he went on, but soon robbers, drawn by the few things he carried (clothes, vessels and objects for worship), attacked him and his companions. The bishop and the deacon died; Willibert, whose skull had been crushed, was miraculously healed.

Saint Desiderius was buried in the oratory, and his veneration is attested in 727 by a charter of the abbey of Murbach. The pilgrims who came because of Willibert's healing took to calling on him against headaches, from migraines to ailments of the mind, and against toothache. His body rests in the church of Saint-⁠Dizier at Saint-⁠Dizier-⁠l'Évêque. He is commemorated on 18 September, by the Western calendar (new style), as a saint of the undivided Church.