Heresy in the High Middle Ages


By Philip Daileader, Ph.D., College of William & Mary

In the High Middle Ages, Heresy was so common that the Church felt threatened. Any belief other than what the Christian Church said could be regarded as heresy, and a punishable act. It was not illegal yet, but many were executed upon being heretics. However, many of them had a purer belief than the Church wanted them to.

A celtic cross at a medieval church cemetery
Heresy in the High Middle Ages turned into a threat for the Christian Church.
(Image: littlenySTOCK/Shutterstock)

The High Middle Ages witnessed a significant increase in popularity and acceptance of heretics. Heretical movements began as a result of numerous factors, one of which was people’s disappointment in all the reform movements. To understand this disappointment, first, we should know the definition of heresy, the reform attempts, and their results.

Heresy in the High Middle Ages

During the Middle Ages, anyone who opposed the fundamental Christian teachings was regarded as a heretic. For example, if a person did not believe that Christ was both man and God, he was an undoubted heretic. Of course, only Christians could be heretics, not people of other religions. A Jew who did not believe Christ was man and God at the same time had the right to do so because their religious doctrines were different.

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On the other hand, if a person engaged in rituals not approved, but not refused, by the Church, they could be a heretic. The heresy of cases not directly opposing Christian teaching was decided one by one. Thus, some theologians wanted a clearer definition of heresy, and they finally decided that ignorance should be excluded.

bulgarian Rila monastery,built in year 1844
Refusing to believe that Christ was both a man and a God was regarded as heresy. (Image: sunnyfrog/Shutterstock)

From then, a heretic was defined as a person who had wrong beliefs, insisted on them, publicly defended them, refused to accept the truth which was presented to them as a response to their claims, and even tried to convince other people.

In the 11th century, the Church came up with an efficient way of identifying heretics: The Chicken Test. Many heretics refused to kill animals due to reincarnation. They believed that human souls transmigrate into animal bodies and that killing an animal might be equal to killing a human. Therefore, the Church asked accused heretics to kill a chicken, and if they refused, it was proof of their heresy.

Learn more about Jews and Christians.

The Geography of Heresy

During the High Middle Ages, heresy became widespread, especially in some parts of Europe including Southern France, in Northeastern Spain, and Northern Italy. These regions did not host the highest number of heretics by coincidence. They were the witnesses of the Gregorian reforms and their disappointing failure.

The Reform Movements and their Failure

Religious reform movements ebbed and flowed in the 1000s to 1300s A.D. The Cluniac and the Cistercian reforms attempted to improve monastic life but failed. In the end, they looked very similar to what they wanted to improve. The ‘Gregorian reforms’ were another attempt to change the situation, which had limited success and left society more dismayed.

A candle between the shadows of a middle age church
People were disappointed in religious reforms and turned to heresy. (Image: Juando Gonzalez/Shutterstock)

The movement began in the middle of the 11th century, led by the papacy. It was a top-down reform movement that aimed to do what the Cluniac reform proposed. The Gregorian reformers wanted to improve standards and morals for the secular clergy, by enforcing certain rules that had been neglected for a long time. Their first aim was clerical celibacy.

Traditionally, priests were supposed to remain celibate for life. Yet, during the tenth century, the tradition was neglected without much opposition. The Gregorian reformers tried to separate priests and sometimes bishops from their wives to rescue celibacy. Their other goal was to stop simony, the outright sale of important church offices. They wanted to enforce the proper law of appointing bishops by the local clergy, instead of allowing positions to be sold.

Nonetheless, the Gregorian reformers failed to achieve either of their objectives. Disappointed by the outcomes, and empowered by literacy, people became motivated to start a heretical movement

Learn more about Francis of Assisi and the Franciscan Movement.

The Role of Literacy in Heretical Movements

In the Early Middle Ages, people were widely illiterate, and heresy was widely uncommon. Nevertheless, heresy in the High Middle Ages rose as did the number of literate people. They would read the Bible themselves and come to conclusions different from those of the Church. That could be the reason why demanding access to the Bible was a sin and could even indicate heresy.

To conclude, a mixture of disappointment, rage, and attempt to understand the Bible without biased interpretations led to the rise of heresy in the High Middle Ages.

Learn more about the People’s Crusade.

Common Questions about Heresy in the High Middle Ages

Q: What was heresy in the Middle Ages?

In the High Middle Ages, if a person rejected the official teachings of the Church, and refused to believe in fundamental Christian principles, they were regarded as a heretic. Beliefs that did not contrast with the Bible, but were not alleged by the Church could be heresy as well, but not always.

Q: What was the punishment for heresy in the Middle Ages?

Heretics were growing in number in the High Middle Ages, and the Church was not happy about it. Thus, they were trying to find heretics and stop them. Once it was proven that they are heretics, usually, the Church would execute them.

Q: Was heresy a religion?

Heresy rose significantly in the High Middle Ages, and sometimes the accused heretics claimed to follow the ‘real’ Christianity. Thus, many of them considered their belief as a religion and even preached it.

Q: Why did heresy become a crime?

In the 16th and 17th centuries, change of religious beliefs led to a higher rate of crime. Thus, heresy itself was acclaimed as a crime. However, heresy in the High Middle Ages was also a punishable act, and heretics were even executed.

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