From 772 to 804, Charlemagne fought eighteen military campaigns against the Saxons — a Germanic people in what is now northern Germany who refused to give up their gods, their customs, or their independence. The war lasted over thirty years, killed thousands, and ended with mass deportation. Here is the real story of how it started, who fought it, and what it left behind.
For thirty-two years, from 772 to 804, a brutal war was fought in what is now northern Germany. On one side were the Saxons — a Germanic people who had lived there for centuries with their own gods, their own traditions, and their own way of running their communities. On the other side was Charlemagne, the most powerful king in Western Europe, who had decided the Saxons needed to become Christians — whether they agreed to it or not. The conflict went through eighteen separate military campaigns. Thousands of people were killed. At one point, Charlemagne had 4,500 Saxon prisoners executed in a single day. At the end, he deported ten thousand Saxons out of their homeland entirely and moved Frankish settlers in to replace them. The official reason for starting the war was that the Saxons had destroyed a church. But the conflict had been building for years before that. And it all came down to one question: who gets to decide how a people should live?
The Saxons were a Germanic people who had settled in northern Germany before the 4th century. They had their own religion, their own social structure, and their own system of community government — all of which they fought to protect for over thirty years.
Who Were the Saxons?
The Saxons settled in northern Germany sometime before the 4th century. Their territory eventually became three main provinces — Angria, Eastphalia, and Westphalia — grouped together in a region called Saxony. The first time they appear in written history is around 356 AD, where they're mentioned as pirates raiding coastal towns in what are now France and England. That's actually how a lot of early historical groups show up in the record — by causing trouble for people who did write things down. The Saxons didn't keep written records. They passed their history, beliefs, and customs down through spoken word. Because of this, most of what we know about them comes from their enemies, which means those sources have to be read carefully. The Saxons practiced a form of Germanic paganism and had a clear social structure: nobles at the top, then freemen, then lower classes, then slaves. Sacrifices were made to their gods — and later accounts claim these sometimes included human sacrifice, though those accounts come from people who had every reason to make the Saxons look bad. One of the most important parts of Saxon religious life was something called the Irminsul. This was a sacred pillar — sometimes described as looking like a tree — that sat at a major religious site. Scholars think it may have carried similar meaning to the World Tree Yggdrasil from Norse mythology, which was said to stand at the center of the universe. Whatever the Irminsul meant exactly, it wasn't just a religious object. It was connected to Saxon politics, military life, and community identity all at once. It was the center of who they were. The Saxons had no king. Instead, they held assemblies where nobles, freemen, and lower classes all had a voice in decisions about law, politics, and war. For the 8th century, that was a pretty unusual system — and it made them very hard to conquer, as Charlemagne was about to find out.
The Irminsul was the most important religious symbol in Saxon culture. It was a sacred pillar tied to their religion, politics, and military identity. When Charlemagne destroyed it in 772, he was attacking not just a religious object but the heart of Saxon cultural life.
Charlemagne — The King Who Started the War
Charlemagne became King of the Franks in 768, sharing power with his brother Carloman I. The brothers disagreed constantly. Charlemagne wanted to fight wars. Carloman pushed for diplomacy. Then Carloman died in 771, and Charlemagne took over alone — probably the worst news the Saxons ever received. Conquering Saxony wasn't a new idea. Both Charlemagne's grandfather Charles Martel and his father Pepin the Short had tried to subdue the region before him. Both had failed. Charlemagne was determined to succeed. One of his closest advisers, a scholar named Alcuin of York, told Charlemagne directly that forced conversion was pointless. Real faith has to come from a person's own free will, Alcuin argued. You cannot scare someone into genuinely believing something. Charlemagne heard this advice and ignored it. The official trigger for the first campaign was this: the Saxons destroyed a church at a town called Deventer, in what is now the Netherlands. The church had been built specifically to convert the people of the region to Christianity, and those people had allied with the Saxons to protect their traditional religious practices. The Saxons objected to the mission by destroying it. That gave Charlemagne the excuse he needed. But scholars are pretty clear that he was going to find some reason to move against Saxony regardless. The church at Deventer was the spark, but the fire had already been laid.
Charlemagne became the sole King of the Franks in 771 and almost immediately turned his attention to Saxony. His grandfather and father had both failed to conquer the region. He was determined to succeed — and he eventually did, but it took over thirty years.
The First Strike — Destroying the Irminsul
In 772, Charlemagne led his army into Saxony and marched straight to Eresburg — the site of the sacred Irminsul. He destroyed it, looted the shrine's treasury, and massacred the people there. This was not just a military move. It was a calculated psychological attack. Destroying the Irminsul was like tearing the heart out of Saxon religious and cultural identity all at once. The shrine had collected a significant amount of treasure from offerings over many years, and Charlemagne took all of that too. He then took hostages from the Saxon leadership and told them to behave. Then he left to deal with other problems. The Saxons did not behave. While Charlemagne was in Italy conquering the Lombards (which he did in 774, adding another title to his growing list), the Saxons came back to Eresburg, destroyed the Frankish fortifications there, and attacked a monastery — paying back the destruction of the Irminsul in kind. Charlemagne turned around, came back, defeated them again in 775, built new garrisons, and left again. This cycle — Charlemagne wins, Saxons rebuild, Charlemagne comes back, Charlemagne leaves, Saxons rebel again — was the basic pattern of the next thirty years. A big reason it kept repeating was structural. The Saxons had no central king, no central government, and no single capital. Defeating one Saxon leader or destroying one settlement didn't end anything. There were always more farmsteads, more extended family groups, more warriors ready to start again.