Egidio Antoniini surnamed of Viterbo, Latin patriarch of Constantinople, was born at Viterbo in the second half of the 15th century. He was received into the order of the hermits of St. Augustine at the early age of ten years; was professor of philosophy and theology in several towns of Italy, and became one of the most eloquent preachers of his epoch. Having become general of his order in 1507, he was appointed patriarch of Constantinople, and bishop of Viterbo, Nepi, Castro, and Sutri. In 1512 he opened, by order of pope Julius II, the Council of Lateran, and on this occasion severely censured the corruption prevailing in the Church, and, in particular, among the clergy. In 1517 pope Leo X sent him to Germany, and appointed him cardinal; in the following year he was sent as papal legate to Spain. Egidio was well versed in the Oriental languages, and a good Latin poet. He wrote a commentary to the first three chapters of Genesis and to several psalms, Latin dialogues, epistles, and poems, and a treatise De ecclesia incremento. Some of these works are given in Martene et Durand, Amplissima Collectio veterans monumentorum, tom. 3. — Hoefer, Nouv. Biogr. Gener. 15:718.