 Ursinus later became the abbot of the monastery of Saint-Martin, where he spent the rest of his days.During his tenure he built a basilica, which became a place of honor to such a degree that in 782 it received the relics of sainted Leodegar.Ursinus also commissioned the monk Defensor to compile the florilegium "Liber scintillarum" from the patristic writings in the abbey's collection.