What is heresy?

In the medieval period, heresy was an opinion about the teaching of the Catholic church, which was condemned by the church as inconsistent with it.


From the early 11th century, many people accused of heresy were burned at the stake as a result. In 1022, people who were considered heretics were burned for the first time since antiquity.

Where and when did religious heresy originate?

Heresy originates in the early 11th century, slowly at first – then, more and more people were accused of holding heretical beliefs. There are two major reasons for that.

Firstly, it may have been the case that people accused were in conflict with the ecclesiastical authority – priests who were causing problems for their bishops by being outspoken about the shortcomings of the church. In this case, being accused of heresy was about ecclesiastical discipline.

Secondly, lay people who were accused may have been in conflict with the church over property or revenues. From the late 11th century, the Roman church went through a process of reform – based, in the first place, on the demands that its appointments should be made without the intervention of secular authority, and that its priests should be celibate.

The first meant that considerable wealth – ie land – was at the disposal of the church. That was acceptable to the lay nobility on the basis of clerical celibacy, so that churchmen could not use church land to found rival dynasties.

However, there were those purists who didn’t want to compromise, and so they had to be weeded out. For example, priests who refused to compromise were condemned. This was the main source of accusations of heresy in the 12th century.

But it’s important to note that heresy wasn’t just about the church. In fact, the people who moved fastest against accused heretics were lay rulers, not churchmen.

And it’s not just about religion – from the 12th century onwards, persecution became more extreme against lepers, sodomites, prostitutes and Jews. And that sort of thing has been going on ever since.

Who were heretics?

It’s impossible to group them over such a huge time period. If you visit the south of France today, you’ll see there’s huge tourist activity that rotates around the word Cathars, referring to a Christian sect that believed the devil made the world and everything in it, and that the sacraments of the church were not true sacraments of Christ, but devilish frauds of a church of the wicked.

But people who were called heretics were not called Cathars in the Middle Ages.

There is a disagreement between historians about whether it’s right to call these people Cathars. Why does that matter? Because if you simply call all heretics Cathars then you are implying that they are part of a European-wide movement – an ‘anti-church’ group pitted against the Roman church.

What did heretics believe?

Every group believed different things.

There is a widely held assumption that heretics who were burned in southern France were part of a Europe-wide heretic movement, who believed there were two gods: one good, and one evil.

Most heretics – the ones we can identify, that is – tended to believe a very simple form of Christianity, based on literal readings of the New Testament.

They placed high value on chastity, and were opposed to any ostentatious wealth and to the wealth and power structure of the church.

That’s where they came into conflict with the church.

How were heretics treated?

This changed over time. The usual assumption is that the Middle Ages was the ‘age of faith’, when people hated heretics. But there is no indication that heretics did not get on and coexist with Catholics until outsiders such as crusaders and inquisitors came in.

For example, the 20-year Albigensian crusade, which began in 1209, was accompanied and followed up by persecution.

How many people were burned for being heretics?

It is impossible to say how many people were burned to death after being accused of heresy, but we do know that on many occasions heretics were burned in large groups – sometimes 200 at a time. That gives you an idea of the scale.

Until around 1160 only a small number were put to the stake. And they would have been alleged to be leaders of heretic groups.

From then onwards, you start to see ordinary people being put to death too.

Is heresy comparable to the witch craze?

In the case of witches, between the 15th and 18th centuries people were put to death all over Europe, usually by burning, on the basis of a belief that they were agents and worshippers of the devil.

This was a fantasy, dreamed up by scholars, churchmen, lawyers and others, but it was based on reality to the extent that in every small community, quarrels, rivalries, jealousies and so on are expressed through allegations that some people are using magical powers to harm their neighbours.

Witch hunters and magistrates interpreted such stories as evidence of the Satanic activity in which they believed. Similarly, there were always groups of people who had unusual religious beliefs and practices, which could be interpreted as ‘heresy’.


This article was first published by HistoryExtra in January 2014