The Catholic Church has excommunicated some of its adherents throughout its existence for various reasons, including heresy, schism, and disobedience to the Church or its teachings.
In Roman Catholic canon law, excommunication is a censure and thus a "medicinal penalty" intended to invite the person to change behavior or attitude that incurred the penalty, repent, and return to full communion. Excommunication severs one from communion with the Church; excommunicated Catholics are forbidden from receiving any sacrament and refused a Catholic burial, but are still bound by canonical obligations such as attending Mass or fasting seasonally. Excommunicated Catholics, however, are barred from receiving the Eucharist or from taking an active part in the liturgy (reading, bringing the offerings, etc.).
Henry IV, Holy Roman Emperor, with 5 separate excommunications from 3 different popes, carries the distinction of publicly being the most excommunicated individual. In this list below there are two popes (Honorius I and Leo I) and seven Catholic saints (Leo I, Athanasius, Columba, Romuald, Arialdo, Joan of Arc, Mary Mackillop) who were issued an excommunication by a church authority.
This list only includes excommunications acknowledged or imposed by a decree of the pope or a bishop in communion with him. excommunications, those that automatically affect classes of people (members of certain associations or those who perform actions such as directly violating the seal of confession or carrying out an abortion), are not listed unless confirmed by a bishop or ecclesiastical tribunal with respect to certain individuals.
1st Millennium 1st century Simon Magus, for attempting to purchase apostleship and for whom simony was named. He is also alleged to have founded Gnosticism by certain Church Fathers. An unnamed Corinthian who had married a woman who had been his father's wife as recounted in . Hymenaeus and Alexander, excommunicated by Saint Paul the Apostle as recounted in 1 Timothy.
2nd century Valentinus, originator of Valentinianism. Marcion of Sinope, originator of Marcionism, excommunicated by Pope Pius I. Montanus, originator of Montanism. Theodotus of Byzantium, proponent of Adoptionism, excommunicated by Pope Victor I.
3rd century Sabellius, originator of Sabellianism. Novatian, an early antipope who taught Novatianism. Paul of Samosata, excommunicated by a synod at Antioch in 269. Bishop Marcellus of Ancyra, excommunicated in 336 for believing in a modified form of Sabellianism by a bishops' synod in Constantinople led by Arian bishop Eusebius of Nicomedia. Pope Julius I argued for his innocence to the bishops who excommunicated him, and in 343 the Council of Serdica found Marcellus' book to be without heresy, but Marcellus was never reinstated as bishop nor formally reconciled. Felicissimus, a Carthaginian deacon, was excommunicated by Cyprian, Bishop of Carthage. Cyprian was in hiding at the time from persecution and he sent people to distribute alms to those hurt by the persecutions. Felicissimus tried to frustrate the efforts of those distributing alms as he saw it as an encroachment on his office.
4th century
Arius, Cyrenaic presbyter, namesake of Arianism. Celestius, early Pelagian leader. Roman Emperor Theodosius I was excommunicated by the Bishop of Milan, Saint Ambrose, for authorizing the Massacre of Thessalonica.Attwater, Donald and Catherine Rachel John. The Penguin Dictionary of Saints. 3rd edition. New York: Penguin Books, 1993. . After repentance, penance and restitution, the Emperor was restored to communion with the Church. Supporters of Antipope Ursicinus were excommunicated by a Roman synod after they accused Pope Damasus I of adultery in a Roman court in 378. Auxentius of Milan, an Arian bishop, was excommunicated by the Roman synod of 369. Saint Athanasius was excommunicated by Pope Liberius allegedly for refusing to attend a synod. Athanasius believed the pope was acting under duress (the pope had been exiled from Rome) and refused to accept the validity of the excommunication.McCASHEN, G. (2023). Liberius, Athanasius and the Roman Synod. The Journal of Ecclesiastical History, 74(1), 1-17. doi:10.1017/S0022046922000446 Some Egyptian monks, by Theophilus I of Alexandria. Four of these monks, namely the Tall Brothers, went to Constantinople, where their presence resulted in accusations made against John Chrysostom.
5th century Archbishop Nestorius of Constantinople, founder of Nestorianism. Archimandrite Eutyches, founder of Eutychianism, along with his monastery, was excommunicated by Archbishop Flavian of Constantinople. Pope Dioscorus I of Alexandria, who presided over the Robber Council of Ephesus. Patriarch John of Antioch and his party by the Council of Ephesus in 431. Peter the Tanner, Patriarch of Antioch was excommunicated by Pope Felix III at a synod in Rome for heresy. Peter Mongus, Patriarch of Alexandria was excommunicated by Felix III. Patriarch Acacius of Constantinople was excommunicated by Felix III on account of his receiving the excommunicated Peter Mongus into communion. This led to the Acacian schism. Papal legates that were sent by Pope Felix III to Constantinople were excommunicated by Pope Felix III. They were sent to call Acacius to explain his conduct and urge the Byzantine Emperor to depose Peter Mongus from his see. After being imprisoned and threatened after arriving at Constantinople, they caved in and held communion with heretics, which led to the pope excommunicating them. Monks in Constantinople were excommunicated by Nestorius, Archbishop of Constantinople, on account of their opposition to his teachings. This took place before Nestorius himself was excommunicated by the Council of Ephesus. The monks appealed to the Emperor Theodosius II to help them against Nestorius, who later summoned the Council of Ephesus. Ibas of Edessa was excommunicated by the Robber Council of Ephesus in 449. This council and its decisions were themselves overturned two years later at the Council of Chalcedon. Theodoret, Bishop of Cyrrhus, was excommunicated by the Robber Council of Ephesus. This council and its decisions were themselves overturned two years later at the Council of Chalcedon. Pope Leo I was excommunicated by Dioscorus I, Patriarch of Alexandria and ten bishops. Pope Leo would later excommunicate Dioscorus and all others who participated in the Robber Council of Ephesus. Classicianus, a Roman official was excommunicated along with his entire household by a bishop named Auxilius after he had entered a church to seize several perjurers. Classicianus wrote afterwards to Augustine of Hippo to intercede for him to Auxilius. Augustine then wrote to Auxilius on Classicianus's behalf.Rachel Stone, Canon law before canon law: using church canons, 400-900 AD Paper presented to CLANS (Cambridge Late Antiquity Network Seminar), 11 February 2014
6th century , Bishop of Vannes was excommunicated after he abandoned his episcopacy and religious vows to become Count of Vannes in 560.Gregory of Tours, A history of the Franks, Pantianos Classics, 1916 King Charibert I of Paris by Bishop Germain of Paris for immorality. Saint Columba was excommunicated in 562 by the synod of Teltown for allegedly praying for the winning side in an Irish War. The excommunication was later held to be an abuse of justice and the bishops in question removed their charge.Adomnan of Iona, Life of St Columba. Ed. by Richard Sharpe. Penguin Books, Toronto, 1995. The sons of Conall mac Domnaill by Saint Columba some time in the late sixth century, due to their persecution of churches. Archbishop Theodore of Mopsuestia by the Second Council of Constantinople. , Count of Tours, by a synod of bishops in 581 on account of creating scandals and false accusations he made against Bishop Gregory of Tours. A layman named Pelagius was excommunicated by Gregory of Tours in the late sixth century after the former had beaten and robbed some of Gregory's men. Gregory later received him back into communion after he and others made oaths.Gregory of Tours. A history of the Franks. Pantianos Classics, 1916 Eulalius, future Count of Auvergne was excommunicated by Cautinus, Bishop of Clermont as a young man as a result of suspicion of murdering his mother. He protested his innocence and Cautinus agreed to allow him to return to communion. Basina, daughter of Chilperic I, her cousin Chrodield, daughter of the previously excommunicated Charibert I, and their party were excommunicated by a synod of bishops who condemned them for a violent monastic rebellion at Holy Cross Abbey in Poitiers in 589.
7th century Ecumenical Patriarch Pyrrhus of Constantinople was excommunicated in 648 by Pope Theodore I and a synod of bishops after he had gone back on his recantation of monothelitism. The pope and the bishops also declared him deposed from his see. Theodore reportedly signed the excommunication upon St Peter's tomb using ink that was mingled with drops of Communion wine.Andrew J. Ekonomou. Byzantine Rome and the Greek Popes, Lexington books. Toronto, 2007. p99 Ecumenical Patriarch Paul II of Constantinople was excommunicated and deposed from his see in 649 by Pope Theodore I after he had professed Monothelitism. Pope Honorius I was posthumously named as excommunicated by the Third Council of Constantinople and by Pope Leo II in a 682 letter to Byzantine Emperor Constantine IV.Andrew J. Ekonomou. Byzantine Rome and the Greek Popes, Lexington books. Toronto, 2007. John Philoponus was posthumously named excommunicated by the Third Council of Constantinople. He was condemned by the council as being a 'tritheist'. An unnamed nobleman was excommunicated by Cedd, Bishop of London on account of an unlawful marriage he was in. According to Bede, this noble was one of the assassins of Sigeberht the Good.
8th century Mystic preachers Aldebert and Clement by a German council headed by Saint Boniface in 745. Clement's excommunication was subsequently upheld by Rome, while Aldebert's was not. The Second Council of Nicaea posthumously excommunicated a number of clergy and theologians by name who had centuries past, some of whom had already been condemned, including: Arius and his followers, Macedonius I of Constantinople, Nestorius and his followers, Eutyches, Dioscorus, Severus of Antioch and Peter the Fuller along with those with them, Origen, Didymus the Blind, Evagrius Ponticus, as well as Sergius I of Constantinople, Pyrrhus of Constantinople, Pope Honorius I, Cyrus of Alexandria, and Macarius I of Antioch along with their followers. A diaconissa named Epiphania was excommunicated by a synod in Rome in 721 that dealt with the issue of illicit conjugal relations.
9th century The Fourth Council of Constantinople excommunicated by name and upheld a number of previous excommunications of previous councils of a number of people who had died in previous centuries. Those names in this list were: Arius and his followers, Macedonius I of Constantinople, Nestorius, Eutyches, Dioscorus, Severus of Antioch, Peter the Fuller, Zoharas the Syrian, Origen, Theodore of Mopsuestia, Didymus the Blind, Evagrius Ponticus, Theodore of Pharan, Sergius I of Constantinople, Pyrrhus of Constantinople, Peter of Constantinople, Paul II of Constantinople, Pope Honorius I, Cyrus of Alexandria, Macarius I of Antioch and his disciple Stephen, Anastasius of Constantinople, Constantine II of Constantinople, Nicetas I of Constantinople, Theodosius III of Ephesus, Sisinnius Pastilas, Basil Tricacabus, Theodoret, Anthony and John (priests of Constantinople) and Theodore Krithinos. Ecumenical Patriarch Photios I of Constantinople was also named as excommunicated by the council.