Ægidius of Viterbo

His Eminence Giles Antonini, O.E.S.A.
Cardinal Priest of San Marcello al Corso
Cardinal Bishop Giles of Viterbo, 17th-century fresco in the Priori Palace, Viterbo, Italy.
Province	Holy See
Diocese	Bishop of Viterbo e Tuscania
Installed	2 December 1523
Term ended	12 November 1532
Predecessor	Ottaviano Visconti Riario
Successor	Giampietro Grassi
Other posts	Prior General of the Order of St. Augustine (June 1507-February 1519) Latin Patriarch of Jerusalem (8 August 1524-19 December 1530) Bishop of Lanciano (10 April 1532-12 November 1532)
Orders
Ordination	ca. 1495
Consecration	December 1523
Created Cardinal	1 July 1517
Rank	Cardinal Priest
Personal details
Birth name	unknown
Born	1472 Viterbo, Papal States
Died	12 November 1532 Rome, Papal States
Buried	Basilica of Sant'Agostino, Rome, Italy
Nationality	Papal States
Parents	Lorenzo Antonini & Maria del Testa

Giles Antonini, O.E.S.A., commonly referred to as Giles of Viterbo (Latin: Ægidius Viterbensis, Italian: Egidio da Viterbo), was a 16th-century Italian Augustinian friar, bishop of Viterbo and cardinal, a reforming theologian, orator, humanist and poet. He was born in Viterbo and died in Rome.

He was born to humble parents and his given name is not known; his father was Lorenzo Antonini, of Canepina, near Viterbo, and his mother, Maria del Testa. He entered the Order of St. Augustine in June 1488 at which time he was given the name Giles. After a course of studies at priories of the Order in Ameria, Padua, Istria, Florence and Rome, where he studied philosophy. He was later made a doctor of theology. In 1506 became Vicar General of his Order. Upon the death of the Prior General, and, under the patronage of Pope Julius II, he was confirmed by election as his successor at three successive General Chapters of the Order: in 1507, 1511 and 1515.

Antonini was a noted preacher, presiding at several papal services at the order of Pope Alexander VI. He also traveled widely, due to his responsibilities as head of the Order. This allowed to be in touch with the leading intellectual figures of the period, with many of whom he formed working collaborations. One friend, Giovanni Pontano, dedicated a work to him, entitled Ægidius.