The Hispanic ascetic Priscillian of Avila was the first person to be executed for heresy, only sixty years after the First Council of Nicaea, in 385. He was executed at the orders of Emperor Magnus Maximus, over the procedural objections of bishops Ambrose of Milan and Martin of Tours, who claimed the Churches' right to punish its own.
Over the years, numerous Christian scholars and preachers have disagreed with the Church on various issues or doctrines. When the Church has become aware of these beliefs, they have been condemned as heretical, and with the East-West Schism finalized in the 11th century, and the split in the Western Church in the 16th, each section has identified the others as "heretical". Historically, this often happened when the belief challenged, or was seen to challenge, Church authority, or drew a movement of followers who challenged the established order socially. For entirely secular reasons, some influential people have had an interest in maintaining the status quo or condemning a group they wished to be removed. The Church's internal explanations for its actions were based purely on objection to beliefs and philosophies that ran contrary to its interpretation of the holy scriptures and its official interpretation of holy tradition.
The penalty for a baptized Catholic above the age of 18 who obstinately, publicly, and voluntarily manifests his or her adherence to an objective heresy is automatic excommunication ("latae sententiae) according to Can. 1364 par.1 C.I.C..
A belief that the church has not directly rejected, or that is at variance with less important church teachings, is given the label, sententia haeresi proxima, meaning "opinion approaching heresy." A theological argument, belief, or theory that does not constitute heresy in itself, but which leads to conclusions which might be held to do so, is termed propositio theologice erronea, or "erroneous theological proposition." Finally, if the theological position only suggests but does not necessarily lead to a doctrinal conflict, it might be given the even milder label of sententia de haeresi suspecta, haeresim sapiens, meaning "opinion suspected, or savoring, of heresy."
Some significant controversies of doctrine have risen over the course of history. At times there have been many heresies over single points of doctrine, particularly in regards to the nature of the Trinity, the doctrine of transubstantiation and the immaculate conception.
The Church has always fought in favor of orthodoxy and the Pope's authority as the successor of St. Peter to determine truth. At various times in history, it has had varying degrees of power to resist or punish heretics, once it had defined them.
In the early church, heresies were sometimes determined by a selected council of bishops, or ecumenical council, such as the First Council of Nicaea. The orthodox position was established at the council, and all who failed to adhere to it would thereafter be considered heretics. The church had little power to actually punish heretics in the early years, other than by excommunication, a spiritual punishment, or, as in the case of Arius, assassination. To those who accepted it, an excommunication was the worst form of punishment possible, as it separated the individual from the body of Christ, his Church, and prevented salvation. Excommunication, or even the threat of excommunication, was enough to convince many a heretic to renounce his views. Priscillian achieved the distinction of becoming the first Christian burned alive for heresy in 385 at Treves.
In later years, the Church instituted the Inquisition, an official body charged with the suppression of heresy. The Inquisition was active in several nations of Europe, particularly where it had fervent support from the civil authority. The Albigensian Crusade (1209-1229) was part of the Roman Catholic Church's efforts to crush the Cathars. It is linked to the movement now known as the Medieval Inquisition. The Spanish Inquisition was particularly brutal in its methods, which included the burning at the stake of many heretics. However, it was initiated and substantially controlled by King Ferdinand of Spain rather than the Church; King Ferdinand used political leverage to obtain the Church's tacit approval. Another example of a medieval heretic (according to some, proto-protestant) movement is the Hussite movement in the Czech lands in the early 1400s.
It is widely reported that the last person to be burned alive at the stake on orders from Rome was Giordano Bruno, executed in 1600 for a collection of heretical beliefs including Copernicanism and (probably more important) an unlimited universe with innumerable inhabited worlds. The last case of an execution at an auto de fe by the Spanish Inquisition was the schoolmaster Cayetano Ripoll, accused of deism and executed by garroting July 26, 1826 in Valencia after a two-year trial.
