Christian feast day: Serapion of Thmuis

The Sacramentary of Serapion of Thmuis is a work of Saint Serapion, bishop of Thmuis in the Nile Delta and a prominent supporter of Athanasius in the struggle against Arianism. He is sometimes called Serapion the Scholastic for his learning. He is best known in connection with this prayer-book or sacramentary (euchologion) intended for the use of bishops.