- Source: Illidius
Saint Illidius (French: Saint Allyre, Alyre; died 385) was a 4th-century bishop of Clermont, France. To Illidius is attributed the rise of Clermont-Ferrand as a center of religious teaching and culture.
Gregory of Tours mentions Illidius in his work. Illidius is credited with having cured the daughter of the Roman Emperor Magnus Maximus at Trier, and died on the return journey.
His tomb attracted many pilgrims.
The fountain of St. Allyre at Clermont is known for its petrifying water, caused by calcareous deposits.