Donatism (Latin: Donatismus, Greek: Δονατισμός Donatismos) was a Christian sect within the Roman province of Africa that flourished in the fourth and fifth centuries among Berber Christians. Donatism had its roots in the social pressures among the long-established Christian community of Roman North Africa (present-day Berber countries Algeria and Tunisia), during the persecutions of Christians under Diocletian. The Donatists (named for the Berber Christian bishop Donatus Magnus) were members of a schismatic church not in communion with the churches of the Catholic tradition in Late Antiquity.
Donatism was an indirect outcome of Diocletian's persecutions. The governor of Africa had been lenient towards the large Christian minority under his rule during the persecutions. He was satisfied if Christians handed over their Scriptures as a token repudiation of their faith. Some Christians acceded to this convenient action. When the persecutions came to an end, however, they were branded traditores, "those who handed (the holy things) over" by the zealous, mostly from the poorer classes.
Like the Novatianist schism of the previous century, the Donatists were rigorists, holding that the church must be a church of "saints," not "sinners," and that sacraments, such as baptism, administered by traditores were invalid. Probably in 311, a new bishop of Carthage, Caecilian, was consecrated by someone who had allegedly been a traditor, Felix of Aptungi; his opponents consecrated a short-lived rival, who was succeeded by Donatus, after whom the schism was named.
In 313, a commission appointed by Pope Miltiades found against the Donatists, but they continued to exist, viewing themselves, and not the Catholic Church, as the "true Church," the only one with "valid sacraments." Because of their association with the Circumcellions, they brought upon themselves repression by the imperial authorities, but they drew upon African regional sentiment, while the Catholic party had the support of Rome. They were still a force at the time of Saint Augustine of Hippo at the end of the fourth century, and disappeared only after the Arab conquest of the 7th–8th century.
The primary disagreement between Donatists and the rest of the early Christian Church was over the treatment of those who renounced their faith during the persecution under the Roman emperor Diocletian (303–305), a disagreement that had implications both for the Church's understanding of the Sacrament of Penance and of the other sacraments in general.
The rest of the Church was far more forgiving of these people than the Donatists. The Donatists refused to accept the sacraments and spiritual authority of the priests and bishops who had fallen away from the faith during the persecution. During the persecution some Church leaders had gone so far as to turn Christians over to Roman authorities and had handed over religious texts to authorities to be publicly burned. These people were called traditores ("people who had handed over"). These traditors had returned to positions of authority under Constantine I, and the Donatists proclaimed that any sacraments celebrated by these priests and bishops were invalid.
The first question, therefore, was whether the Sacrament of Penance can effect a reconciliation whereby the apostate, or in some cases specifically the traditor, may be returned to full communion. The orthodox Catholic position was that the sacrament was for precisely such cases, though at the time the Church still followed the discipline of public penance whereby a penitent for such a grievous offence would spend years, even decades, first outside the doors of the church begging for the prayers of those entering, then kneeling inside the church building during services, then standing with the congregation, and finally receiving the Eucharist again in a long progress toward full reconciliation. The Donatists held that such a crime, after the forgiveness of Baptism, disqualified one for leadership in the Church, a position of extreme rigorism.
The second question was the validity of sacraments celebrated by priests and bishops who had been apostates under the persecution. The Donatists held that all such sacraments were invalid; by their sinful act, such clerics had rendered themselves incapable of celebrating valid sacraments. This is known as ex opere operantis, Latin for from the work of the one doing the working, that is, that the validity of the sacrament depends upon the worthiness and holiness of the minister confecting. The Catholic position, according to Augustine, was ex opere operato — from the work having been worked; in other words, that the validity of the sacrament depends upon the holiness of God, the minister being a mere instrument of God's work, so that any priest or bishop, even one in a state of mortal sin, who speaks the formula of the sacrament with valid matter and the intent of causing the sacrament to occur acts validly. Hence, to the Donatists, a priest who had been an apostate but who repented could speak the words of consecration forever, but he could no longer confect the Eucharist. To Catholics, a person who received the Eucharist from the hands of even an unrepentant sinning priest still received Christ's Body and Blood, their own sacramental life being undamaged by the priest's faults.
As a result, many towns were divided between Donatist and non-Donatist congregations. The sect had particularly developed and grown in northern Africa. There was growing unrest and threats of riots in Carthage connected to the bishop controversy. Constantine, hoping to diffuse the unrest, gifted monies to the "catholic" bishop Caecilian as payment for church buildings that had been damaged or confiscated during the prior period of persecution. No gifts were made to the Donatists (it appeared that Constantine was not fully aware of the seriousness of the dispute, thus his gifts only made matters worse). The Donatists appealed to Rome for equal treatment; Constantine tasked Miltiades to sort the issue which led to the 313 commission mentioned above. The Donatists refused to abide by the decision of the Roman Council and demanded a local council to hear the dispute. This attempt failed to produce a good hearing and the Donatists appealed directly to the Emperor. From his letter that survives, Constantine shows frustration that the church cannot come to a good conclusion and he calls for a larger council, what is now known as the Council of Arles in 314. Again, the decision went against the Donatists and again they appealed to Constantine. The Emperor demanded that all parties be brought to Rome for a hearing; Constantine ruled in favor of Caecilian and warned against unrest. A delegation from Rome traveled to Carthage to seek a compromise - this trip failed miserably. Donatist extremists were stirring up protests and violence in the streets. The Donatists refused to accept any compromise or decision in favor of the "catholic" bishop.
After the Constantinian shift, when other Christians accepted the emperor as a leader in the Church, the Donatists continued to see the emperor as the devil. After several attempts to bring reconciliation, in 317 Constantine issued a severe edict that threatened the death penalty to anyone who disturbed the peace of the empire. Another edict followed that called for the confiscation of all Donatist church property. In Carthage Donatus refused to surrender buildings and the local Roman governor called for a "police" action, sending troops in to deal with the Donatists. The historical records are unclear, but it appears that some Donatists were killed and clergy were sent into exile. Outside of Carthage, however, Donatist churches were left undisturbed and the clergy were allowed to remain in place. Ultimately Constantine's efforts to bring unity between the "catholics" and the Donatists failed, and by 321 Constantine granted toleration to the Donatists. In an open letter to the "catholics" Constantine asked the bishops to show moderation and patience to the Donatists.
The Donatists also drew their beliefs from the writings of Tertullian and Cyprian. St. Augustine of Hippo campaigned against this unorthodox belief throughout his tenure as Bishop of Hippo, and through his efforts the orthodox Catholic Church gained the upper hand. Augustine's view, which was also the majority view within the Church, was that it was the office of priest, not the personal character of the incumbent, that gave validity to the celebration of the sacraments.
In 409, Marcellinus of Carthage, Emperor Honorius's secretary of state, decreed the Donatists heretical and demanded that they give up their churches. This was made possible after a collatio, in which St. Augustine, with legal documents, proved that Emperor Constantine had chosen the Catholic Church over the Donatists as the official church of the empire. As a result the Donatists were harshly persecuted by the Roman authorities, and even Augustine protested at their treatment.
Nevertheless, the effects of Augustine's theological successes and the emperor's legal action were somewhat reversed when the Vandals conquered North Africa. Donatism survived the Vandal occupation and the Byzantine reconquest under Justinian I. It is unknown how long Donatist belief persisted but some Christian historians believe the Donatist schism and the discord it caused in the Christian community made easier the Arab conquest of the region in the 7th century.
Donatists followed a succession of bishops.
- Majorinus (311–15)
- Donatus II Magnus (315–55; exiled 347)
- Parmenianus (355–91)
- Primian (391–93), 1st time
- Maximianus (393–94)
- Primian (394–c. 400), 2nd time
John Wycliffe taught that the moral corruption of priests invalidated their offices and sacraments, which was the same belief that had originally characterized Donatism.  The later reformers partially distanced themselves from Wycliffe's view of the sacraments precisely because of its Donatistic undertones. 
During and after the Reformation, the word "Donatist" (sometimes "neo-Donatist") was commonly used by the magisterial reformers as an incriminating label for the more radical reformers such as the Anabaptists. Conservative Lutherans are sometimes labeled Donatist by liberal Lutherans, as a reference to their doctrine of church-fellowship and position that churches which deny that Jesus’ true Body and true Blood are eaten during the Eucharist do not celebrate a valid Lord's Supper.
- Norman F. Cantor, The Civilization of the Middle Ages, 1995:51f.
- Cantor. 1995:51.
- Cross, FL, ed. (2005), "Novatianism", The Oxford dictionary of the Christian church, New York: Oxford University Press.
- Cross, FL, ed. (2005), "Donatism", The Oxford dictionary of the Christian church, New York: Oxford University Press.
- Frend 1952, pp. 144-45 The remainder of this paragraph comes from Frend's text which continues to be seen as an authority text. Frend gets his chronology of events mainly from the work of Optatus, "Against the Donatists," a biased presentation, but one of the only surviving ancient sources for these events.
- Frend 1952, pp. 144-45.
- Frend 1952, p. 156.
- Frend 1952, p. 157.
- Frend 1952, pp. 159-160.
- Frend 1952, pp. 161-162; from the Letters of Constantine preserved by Optatus.
- Template:Augustine, Letter 134, Section 2.
- "Donatism", Concordia Cyclopedia, CMU.
- Herring, George. Introduction To The History Of Christianity. New York: New York University Press, 2006, p230.
- Pelikan, Jaroslav. Credo: Historical and Theological Guide to Creeds and Confessions of Faith in the Christian Tradition. Yale University Press, 2003, p474.
- Verduin, Leonard. "1". The Reformers and Their Stepchildren. ISBN 0-8028-3791-3.
- The doctrine of church fellowship, Reclaiming Walther.
- Metzger, Paul W, What Constitutes A Valid Celebration Of The Lord’s Supper? (PDF).
- Daniel, Robin (2010), This Holy Seed: Faith, Hope and Love in the Early Churches of North Africa, Chester: Tamarisk Publications, ISBN 978-0-9538565-3-4.
- Frend, WHC (1952), The Donatist Church: A Movement of Protest in Roman North Africa, Oxford University Press, ISBN 0-19-826408-9.
- Tilley, Maureen A (1997), The Bible in Christian North Africa: The Donatist World, Fortress Press, ISBN 0-8006-2880-2.
- Tilley, Maureen A, ed. (1996), Donatist martyr stories: the Church in conflict in Roman North Africa, Liverpool University Press, ISBN 0-85323-931-2.
- Cameron, Michael (2001), "Augustine’s Use of the Song of Songs Against the Donatists", in van Fleteren, Frederick, Augustine: Biblical Exegete, New York: Peter Lang.
- Corcoran, John Anthony (1997), Augustinus Contra Donatistas, Donaldson: Graduate Theological Foundation.
- Keleher, James P. (1961), Saint Augustine’s Notion of Schism in the Donatist Controversy, Mundelein: Saint Mary of the Lake Seminary.
- Lewis, Gordon R., "Violence in the Name of Christ: The Significance of Augustine’s Donatist Controversy for Today", Journal of the Evangelical Theological Society 14, no. 2 (Spring 1971): 103–110.
- Paas, Steven (2005), A Conflict on Authority in the Early African Church: Augustine of Hippo and the Donatists, Zomba: Kachere Series.
- Russell, Frederick H. (1999), "Persuading the Donatists: Augustine’s Coercion by Words", in Klingshirn, William E., Limits of Ancient Christianity: Essays on Late Antique Thought and Culture in Honor of R. A. Markus, Ann Arbor: University of Michigan Press.
- Scalise, Charles J., "Exegetical Warrants for Religious Persecution: Augustine vs. the Donatists", Review & Expositor, 93, no. 4 (Fall 1996): 497–506.
- Shimmyo, Theodore T., "St Augustine’s Treatment of the Donatist Heresy: An Interpretation", Patristic and Byzantine Review, 10, no. 3 (1991): 173–182.
- Park, Jae-Eun, "Lacking Love or Conveying Love? The Fundamental Roots of the Donatists and Augustine’s Nuanced Treatment of Them", The Reformed Theological Review, 72, 2 (Aug 2013): 103-121.
- Donatus & the Donatist Schism, Early Church, a list of primary and secondary sources on the Donatists.
- "Donatists", Catholic Encyclopedia, goes into some detail about the politics in the early church that was the background for the rise and fall of Donatism.
- Letter of Petilian of Cirta, Sean Multimedia, actual letter written by a Donatist leader.
- Andrew H. Merrills, Vandals, Romans and Berbers: New Perspectives on Late Antique North Africa, Ashgate Publishing, Ltd., 2004 - new analysis of the textual, epigraphic and archaeological record.