The decapitation of Priscillian and some of his followers in Trier was the first case of capital punishment through the Catholic "inquisition" in the history of the Church.
Priscillian was clearly influenced by some sort of doctrine, or perhaps, as I have suggested, a book of some kind. He was visited by a woman who called herself Agape, and a man named Elpidius, who had come from Egypt. These two purportedly had become friendly with a man named Marcus of Memphis, who had connections with Gnosticism.
When I first read Professor Chadwick's book, I knew that this story was too good to remain in theological and scholastic obscurity. It was the stuff of best-sellers and I knew I would have to write it myself. The result was Pilgrimage to Heresy which has now been translated into Spanish and published as Peregrinos de la Herejia.
Priscillian gathered an immense following. His message brought men and women from all walks of life to his gnostic message of salvation, and not only from Galicia but throughout Spain, specially the north, into the south of France and even the northern states of Italy. For the Priscillianists, friendship with the world was friendship with the devil and thus enmity with God. He who called himself the Creator God was deluding himself since he had originated in a lie; however, humankind could not blame the Devil for his sins as he did retain free-will and had an obligation to extricate his soul from its earthly bondage by the practice of true Christianity and the reading and study of the Bible, `day and night`. Merely nominal Christianity was not enough. The resurrection of the body, Priscillian taught, was achieved by the realisation of the spirit. Thus, by implication, there could be no bodily resurrection of Christ in the literal sense. The material world, he wrote is `short-lived and evil`. Finally and perhaps most importantly, the true God would eventually reclaim all spirits back to his bosom and this earthly realm, and the false, blind trickster Samael would cease to be.
The Priscillianists were vegetarians, abstained from wine, and practiced voluntary poverty and celibacy. Priscillian said that men and women were equal as their spirits were equal and that slavery was horrific and must be abolished. We are talking 1700 years ago here!
Not surprisingly, he had enemies. Priscillian's most notable opponents were Hydatius of Emerita Augusta (present day Merida), and Ithacius of Ossonuba (present day Faro in the south of Portugal). Between them, they petitioned Gratian, the then Emperor (soon to be killed by Maximus “The Usurper”, who denied any involvement in Gratian’s death), and a Synod was held at Saragossa (Zaragoza in Spain) in 381. The Synod was not well attended, however, which begs the question as to whether Hydatius and Ithacius’charges were of much interest to the rest of the Iberian bishops, and neither Priscillian, nor any of his followers attended. A late message from the Pope absolved the Priscillianists of all possible charges since they had not been there to defend themselves. They were most certainly not, as I have read on the Internet, “ex-communicated” at this Synod, as was put about by Priscillian's accusers.
It was well known that Hydatius had a wife and likely one or more children. He kept himself surrounded with a mafia-like protection unit. Many of his congregation had refused to take communion with him. But he was clearly disturbed at the Priscillianist presence and wrote to his Metropolitan Ithacius to complain. After a Priscillianist delegation by Bishops Instantius and Salvianus to Hydatius in Merida was turned away - and in which, the bishops were bodily thrown out of Hydatius’ presence - they appointed Priscillian Bishop of Ávila. Appalled and likely worried for their own survival, Hydatius and Ithacius appealed to the Emperor Gratian, who issued a rescript threatening the Priscillianists with banishment. Consequently, the three Priscillian bishops went in person to Rome, to present their case before Damasus the Pope. Despite being refused an audience with either pope or emperor, some exchange of what was likely a considerable amount of money to the imperial questor secured the restoration of their churches.
Ithacius, Priscillian's main accuser, fled to Trier fearing that he would answer himself for his charges against a fellow bishop. But the die was caste. What had essentially begun as a church matter, now attracted the attention of the secular arm. It was ultimately to prove Priscillian’s downfall.
The murder of Emperor Gratian in Lyon and the accession, at Trier (Trèves, in Germany) of the usurper Magnus Maximus (383) was to cause the tide to turn against the Priscillianists. Maximus was a soldier who had no interest in church matters, but he was bound to listen to Ithacius' - who was now returned from exile - complaints. In consequence of his representations a new synod was held (384) at Bordeaux. The Priscillianists had dangerous enemies in the Aquitaine and faced a hung jury. Instantius was sent into exile in the Scilly Isles. Salvianus had died while the Priscillianists were in Rome and so was spared the questioning.
Priscillian, knowing that his protestations would meet with no sympathetic hearers, appealed directly to Maximus, but the Emperor had other concerns to deal with, not least of which building up his coffers after an expensive war.