Birth. (No date or place found). He is also listed as Cidonato.

Education. (No information found).

Birth. (No date or place found). He is also listed as Eustase; as Eustrasio; as Eustazio; and as Eustachio.

Education. (No information found).

Cardinalate. Bishop cardinalis of Albano in 761. Consecrated (no information found). Together with Bishops Citonato of Porto and Gregorio of Palestrina, he consecrated Antipope Constantine in 767.

Death. 769, (no place found). Buried (no information found).

Bibliography. Cardella, Lorenzo. Memorie storiche de' cardinali della Santa Romana Chiesa. Rome : Stamperia Pagliarini, 1792, I, pt. 1, 41; Chacón, Alfonso. Vitæ, et res gestæ Pontificum Romanorum : et S.R.E. Cardinalium ab initio nascentis Ecclesiae usque ad Clementem IX P. O. M. Alphonsi Ciaconii Ord. Praed. & aliorum opera descriptæ : cum uberrimis notis. Ab Augustino Oldoino, Soc. Jesu recognitae, et ad quatuor tomos ingenti ubique rerum accessione productae. Additis Pontificum recentiorum imaginibus, & Cardinalium insignibus, plurimisque aeneis figuris, cum indicibus locupletissimis. Romæ : P. et A. De Rubeis, 1677, I, col. 539; Cristofori, Francesco. Cronotasi dei cardinali di Santa Romana Chiesa. Rome : Tipografia de Propaganda Fide, 1888, p. 40; "Essai de liste générale des cardinaux. Les cardinaux des 10 premiers siècles". Annuaire Pontifical Catholique 1926. Paris : Maison de la Bonne Presse, 1926, p. 149, no. 26.

Birth. (No date or place found). He is also listed as Pierre-Guillaume.

Education. (No information found).

Cardinalate. Presbyter cardinalis of the title of S. Sabina in 761.

Death. (No date or place found). Buried (no information found).

Bibliography. Cristofori, Francesco. Cronotasi dei cardinali di Santa Romana Chiesa. Rome : Tipografia de Propaganda Fide, 1888, p. 127; "Essai de liste générale des cardinaux. Les cardinaux des 10 premiers siècles". Annuaire Pontifical Catholique 1926. Paris : Maison de la Bonne Presse, 1926, p. 148, no. 148, no. 21.

Birth. (No date or place found).

Education. (No information found).

Early life. Abbot of the monastery of S. Vito sull'Esquilino, Rome. He was probably adscribed to the liturgical service of the deaconry annexed to that church.

Cardinalate. Presbyter cardinalis of an unknown title in 761(1). Archpriest cardinalis of the Holy Roman Church.

Antipapacy. Elected antipope on July 31, 768 by the Lombard party in opporition to Antipope Constantine, of the party of the duke of Nepi. On that same day, he was forced to abdicate by the followers of Primicerius Cristoforo and returned to his monastery with great reverence. Some sources do not consider him a real antipope. Nothing is known of his life after this episode.

Death. (No place found), Rome (?). Buried (no information found).

Bibliography. Cardella, Lorenzo. Memorie storiche de' cardinali della Santa Romana Chiesa. Rome : Stamperia Pagliarini, 1792, I, pt. 1, ; Chacón, Alfonso. Vitæ, et res gestæ Pontificum Romanorum : et S.R.E. Cardinalium ab initio nascentis Ecclesiae usque ad Clementem IX P. O. M. Alphonsi Ciaconii Ord. Praed. & aliorum opera descriptæ : cum uberrimis notis. Ab Augustino Oldoino, Soc. Jesu recognitae, et ad quatuor tomos ingenti ubique rerum accessione productae. Additis Pontificum recentiorum imaginibus, & Cardinalium insignibus, plurimisque aeneis figuris, cum indicibus locupletissimis. Romæ : P. et A. De Rubeis, 1677, I, col. 540; Cristofori, Francesco. Cronotasi dei cardinali di Santa Romana Chiesa. Rome : Tipografia de Propaganda Fide, 1888, p. 277; Del Re, Niccolò. "Filippo, antipapa." Mondo vaticano. Passato e presente. Città del Vaticano : Libreria Editrice Vaticana, 1995, p. 493; "Essai de liste générale des cardinaux. Les cardinaux des 10 premiers siècles". Annuaire Pontifical Catholique 1926. Paris : Maison de la Bonne Presse, 1926, p. 148, no. 20; Kelly, John Norman Davidson. The Oxford Dictionary of Popes. Oxford ; New York : Oxford University Press, 1986, p. 94-95; Reardon, Wendy J. The deaths of the popes : comprehensive accounts, including funerals, burial places and epitaphs. Jefferson, N.C. : McFarland & Co., Publishers, 2004, p. 59; Regesta pontificum Romanorum ab conditio Ecclesia. Ad annum post Christum natum MCXCVIII. Graz : Akademische Druck- u. Verlagsanstalt, 1956. 2 v. Reprint. Originally published : Lipsiae : Veit et comp., 1885-1888. Original t.p. included : Regesta pontificum Romanorum ab condita ecclesia : ad annum post Christum natum MCXCVIII. Editionem secundam correctam et auctam edidit Philippus Jaffè ; auspiciis Gulielmi Wattenbach; curaverunt S. Loewenfeld, F. Kaltenbrunner, P. Ewald, I, 284; Susi, Eugenio. "Flippo." Enciclopedia dei papi. 3 vols. Roma : Istituto della Enciclopedia italiana, 2000, I, 675-677.