A Spanish 17th-century portrait of Leo I, crowned with papal tiara, holding cross and key, intently gazing out while giving his blessing. His 5th-century pontificate was one of the most important, solidifying the dignity of the papacy by his solemn rule of 21 years. He trumped heretical Pelagians, Manichaeans and others. He used firm and benevolent policy to negotiate cooperation between empires East and West, as well as with Huns and Vandals, notably going out to meet Attila as he marched toward Rome. Because of his remarkable greatness at upholding the Faith in word and deed, he was made a Doctor of the Church in 1754. This is by the artist F. Herrera.