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Feb. 12, 2021

50 – Charlemagne: Conquering Europe

50 – Charlemagne: Conquering Europe

Charlemagne launches wars in all directions and wins them all. Mostly.


When last we left off King Charles of Francia became King of the Lombards, adding the northern half of the Italian peninsula to his vast kingdom. Over the next thirty years Charles created the first great post-Roman, European empire. Under his well-organized, well-equipped military machine, the Franks engaged in near-continual warfare across Francia’s vast borders.

For the purpose of simplicity we’re going to look at four major areas of conflict in turn: Italy, northern Spain, eastern Germania and Saxony. We’re going by region since there is no way to do this chronologically. From 772 to 804 Charles and his generals went back and forth from one campaign to the next in a series of protracted wars. For example: in 785 Charles was fighting the Saxons, in 786 he invaded southern Italy, in 787 he fought the Avars on the fringes of eastern Germania, then in 788 he campaigned in Bavaria and northern Italy. He was easily one of the best multi-taskers in human history, and the kind of guy who would stab a German in Spring and an Italian that winter, while sponsoring churches and promoting education. The Frankish king was playing the long game and continually wore down his opponents while incorporating their territory into his governmental system, religion and culture.

Let’s begin with Italy, of which Charles was in control of the northern half upon becoming King of the Lombards. In 776 two Lombard dukes in northern Italy revolted against their Frankish overlords. The dukes then turned to their fellow Lombard nobles and asked them to rise up against the foreign invader, throw off his yoke, and reestablish the kingdom of their forefathers to which they responded: [crickets chirping]. Charles had left quite an impression on the Lombards. He was just and fair, allowing loyalists to control their own lands as before. And he was also fearsome and persistent, capable of summoning the largest and best-supplied armies in Europe, which were capable of perpetual warfare. Most Lombards realized they had everything to lose and nothing to gain from fighting against their Frankish king and remained faithful to him. That year Charles marched south and easily put down the rebellion, killing at least one of the dukes, and replacing both with Frankish counts.

With northern Italy firmly in control, Charles looked to the southern half which was divided between two countries. The first was the Principality of Benevento. When Charles became King of the Lombards in 774, Duke Arechis II refused to recognize him and declared himself ‘princeps’ of the last remaining independent Lombard territory, which controlled much of Italy’s southern half down to the heel and toe of the peninsula. Those areas and Sicily were minor states loyal to Byzantium. Naturally, the Byzantines were alarmed when Charles became King of the Lombards, Roman Patrician and dominated half of Italy, since they dreamed of reconquering the peninsula and restoring the Roman Empire, and Frankish power directly infringed upon their irrational attachment to past glory. In 781 Constantine VI proposed a marriage between himself and Charles’ daughter Rotrud to safeguard his Italian territory but the Frankish king refused to send her to Constantinople. That same year, Charles passed on his title King of the Lombards to his son Pepin, who ruled under him.

In 786 Charles had enough of Prince Arechis II and won an easy victory over him, turning Benevento into a tributary state under the Lombard’s son Grimoald. This was too much for the Byzantines and in 788 they sent an army to southern Italy. This army was led by Adelchis, son of the deposed King Desiderius. The Byzantines hoped that this ‘prince of nothing’ who had been living in exile in Constantinople would rally the Lombards to his cause and repulse the Franks. A Frankish army joined with Duke Grimoald’s forces and together they defeated the Byzantines and ended any last hopes for an independent Lombard kingdom.

In 797 the Byzantine Empress Regent Irene launched a coup against her son. Her agents gouged out Constantine VI’s eyes and Irene declared herself sole ruler of Byzantium. In these patriarchal times a woman ruling over men did not go over well. The church generally viewed it as an inversion of the natural order. While Irene took a more liberal view of the Scripture, the faithful followed it more literally. Various Italian politicians viewed Irene as illegitimate and in 799 a Sicilian embassy arrived in Aachen, with one official possibly encouraging Charles to invade the island. Pope Leo III declared that the Roman throne was vacant since a woman could not rightfully rule and on Christmas Day 800 he crowned Charles “Emperor of the Romans.” And yes, I will have a lot more to say about this, probably in the next episode. As Emperor of the Romans and his son the King of the Lombards, Charles firmly controlled most of Italy. But he chose not to invade further south, probably because he was more concerned with subduing the Saxons in the north. Instead, Charles and Pepin contented themselves with the northern 3/5ths of the peninsula, while occasionally putting down rebellions in the south.

The next series of wars we’ll look at is along the Pyrenees. By this time the dominant power in Spain was the Emirate of Cordoba. The Emirate was an Islamic country ruled by loyalists to the Umayyad dynasty, even though the vast majority of the Islamic world was controlled by the Abbasids. The Umayyads were generally unpopular since they maintained the supremacy of the Arabs, even though many of their people were of different ethnic backgrounds. In particular, many Muslims along the northeastern border with Francia were resettled Berbers from around modern-day Morocco. In contrast, the Abbasids supported racial equality before the law, naturally making them more popular among the numerous peoples the Arabs had conquered.

In 777 the leaders of Barcelona, Zaragoza and Huesca sent emissaries to King Charles of Francia at Paderborn and asked for aid in overthrowing their Umayyad overlords. The Frank welcomed the news since he aimed to control this troublesome border. For half a century Spanish Muslims, Gascons and Basques had raided into southeastern Francia, and Charles wanted to create a militarized buffer zone, called a marka, or march. The following year Charles and his armies traversed the Pyrenees. Every town and village this massive northern army passed declared for Charles. Barcelona and Girona opened their gates to him. The campaign looked like a spectacular success, with the northeast surrendering without a fight. That is until the Franks reached Zaragoza which shut their gates against the Franks, and whose leader claimed that he had only asked Charles for help and was not prepared to be his vassal. For a month the Franks besieged the city, but given the poor siege equipment of the time they made little progress and Charles called a retreat.

The army went north until they reached Pamplona, which opened its gates to him. The city was controlled by Basques who had submitted to Charles, but the Frankish king worried that as soon as he left they would simply switch sides and go back to raiding Aquitaine. Charles couldn’t abide an enemy stronghold along his southwestern border and he razed the city to the ground alongside numerous other towns along the march home. But the outraged Basques weren’t just going to let the Franks destroy their homes and walk away that easily. First, the Basques naturally wanted revenge against those who had treated them so cruelly. Second, these men were now impoverished, in desperate need of money and supplies and Charles’ army was weighed down with booty. Charles had given thousands of men, many of them trained raiders, the motive and need to attack him.

A sizeable Basque army with intimate knowledge of the terrain slipped past the slow-moving Franks and set up an ambush along the central pass into Aquitaine. There they hid along a wooded ridgeline and waited for the main force to walk through. When they did, the Basques burst out of the trees and attacked the baggage train. The chronicler Einhard called it a total slaughter and many important nobles died in the fighting, including, “Eggihard, the surveyor of the royal table, Anselm, the Count of the Palace, and Roland, Prefect of the Breton frontier.” The Basques seized the Frankish treasures and fled into the surrounding country before the main army could assist.

The Battle of Roncevaux Pass was one of Charles’ only recorded defeats. Today, it is mostly known through the famous Song of Roland, an epic poem composed in the 11th or 12th century that fictionalizes the battle. One of the oldest surviving works of French literature, the tragedy depicts Roland as a chivalrous knight, who bravely fought against an overwhelming Muslim army with his blessed sword Durandal. Which is more than a slight deviation from what actually happened.

Charles was not dismayed by this defeat. In 781 he made his son Louis King of Aquitaine in charge of defending the territory. Meanwhile the Franks led a Christianization program across the Pyrenees. Over the next few decades Louis slowly took more territory with the help of Muslim lords in rebellion against the Emirate. In 785 he conquered Girona and extended his influence into Catalonia proper. This allowed him to create the Marca Hispanica, the Spanish March, which were loyal territories that provided a buffer between Aquitaine and the Emirate of Cordoba. In 797 the governor of Barcelona gave the city to the Franks. The Umayyads retook the city two years later, but Louis besieged it for a full two years and reconquered this important port. By 809 Louis probably took Tarragona before being repulsed at Tortosa. The rugged terrain, strong fortresses and hostile Islamic presence meant that the Franks could only conquer so much. Instead, Charles and Louis created a line of fortifications against the Basques and engaged in penury raids against the Emirate. Finally, at some point the Franks hired Italian sailors to conquer Corsica and the Balearic Islands, the latter of which were frequently used by Muslim pirates. These conquests demonstrate Charles’ vision of his realm as an empire with varied resources. While the Franks composed the main land force, his Italians bolstered his fledgling Mediterranean navy.

Our next series of conflicts were in the east against Bavaria and the Avars just beyond them. Bavaria had been under the Frankish sphere of influence for more than a century. Like the Franks they were Germanic and shared many laws and customs. They were also Catholic and thus the ideal subjects. Moreover, Charles wanted to eliminate its leader who was a potential rival. Duke Tassilo was a fellow grandson of Charles Martel, and King Charles worried that if the duke sensed weakness he could lead enough Franks into rebellion and cause serious problems. Tassilo also developed military alliances that threatened Francia’s expanding borders. In 760 the Duke had married the Lombard princess Liutperga, tying Bavaria and Lombardy together…that is until Charles conquered northern Italy and Liutperga became a princess of nothing. Realizing his straits, in the 780s Tassilo made an alliance with the Pannonian Avars, a confederation of nomads from the Eurasian Steppe who had settled around modern-day Hungary.

Charles claimed that Duke Tassilo was conspiring against him and in 787 he led a three-pronged invasion of Bavaria. The Bavarians couldn’t hope to counter the overwhelming numbers of the Franks and he surrendered without a fight. He swore allegiance to Charles and offered his own son as a hostage. The following year, Charles summoned a number of his vassals to his palace at Ingelheim. At the time, the Avars were raiding into Bavaria and northeastern Italy. Charles claimed that these raids were part of a conspiracy by Tassilo to attack Frankish lands and sentenced him to death. Charles then commuted the sentence as an act of ‘mercy,’ and had him sent to a monastery, where Tassilo was forced to renounce all his claims to lordship. Charles then took Bavaria under his control in a bloodless coup.

Charles assembled his armies and launched a two-pronged invasion of Pannonia through Bavaria and northern Italy. What follows is another demonstration of the Frankish king’s model for conquest that bore a similar pattern to what happened in Spain. When the Franks invaded Catalonia they were merciful to all those who submitted and who they believed they could control. But when Charles passed through Basque territory, even lands that had declared for him, he destroyed their fortresses and burned their towns because he knew that this far-off, mountainous people couldn’t be controlled. In this eastern conflict, Charles accepted Bavarian submission and let the people continue life as normal so long as they acknowledged him as their lord. But the Avars were too far and too different to be controlled, and thus the Franks engaged in a scorched earth policy.

The chronicler Einhard recounts:


“How many battles were fought there and how much blood was shed is still shown by the deserted and uninhabited condition of Pannonia, and the district in which stood the palace of the Kagan is so desolate that there is not so much as a trace of human habitation. All the nobles of the Avars were killed in this war, all their glory passed away; their money and all the treasures that they had collected for so long were carried away. Nor can the memory of man recall any war waged against the Franks by which they were so much enriched and their wealth so increased. Up to this time they were regarded almost as a poor people, but now so much gold and silver were found in the palace, such precious spoils were seized by them in their battles, that it might fairly be held that the Franks had righteously taken from the Avars what they unrighteously had taken from other nations.”


Indeed; the wealth taken from the Avars was so great that it funded the imperial palace at Aachen. Their political union, the Avar Confederation, was in tatters, and the various tribes fought a bloody civil war, further weakening them. In 796 the Italian Duke Eric recognized their plight and plundered their capital. The Avars became so wearied of the devastation that their khagan travelled to Aachen where he submitted to Charles, accepted baptism and promised to convert his people to Christianity. But many Avars resented being a tributary state and converting to a foreign religion and they revolted. But by now the weakened people were caught between the Franks in the west and the Bulgars in the east. Between 803-805 Charles sent Frankish armies east, which ended the Avar Confederation and established the Pannonian March, a tributary territory of petty lords that provided a buffer state between Francia and the Bulgarian Empire. Meanwhile the Croats and Serbs also submitted to the Franks, further protecting Italy from Bulgar aggression.

The final front we’re looking at was Charles’ most famous, most brutal and longest conflict: the Saxon Wars. The Saxons were militaristic, populous and proud. They had great generals and were cunning in battle. Moreover, they were pagan and loathe to adopt Christianity, which meant that even when Charles subdued them, as soon as he left some tribes would inevitably revolt. Each time Charles had to reinvade he enacted more brutal policies.

As Einhard notes,


“The Saxons, like most of the races that inhabit Germania, are by nature fierce, devoted to the worship of demons and hostile to our religion, and they think it no dishonour to confound and transgress the laws of God and man. There were reasons, too, which might at any time cause a disturbance of the peace. For our boundaries and theirs touch almost everywhere on the open plain, except where in a few places large forests or ranges of mountains are interposed to separate the territories of the two nations by a definite frontier; so that on both sides murder, robbery, and arson were of constant occurrence. The Franks were so irritated by these things that they thought it was time no longer to be satisfied with retaliation but to declare open war against them.


The end might have been reached sooner had it not been for the perfidy of the Saxons. It is hard to say how often they admitted themselves beaten and surrendered as suppliants to King Charles; how often they promised to obey his orders, gave without delay the required hostages, and received the ambassadors that were sent to them. Sometimes they were so cowed and broken that they promised to abandon the worship of devils and willingly to submit themselves to the Christian religion. But though sometimes ready to bow to his commands they were always eager to break their promise, so that it is impossible to say which course seemed to come more natural to them, for from the beginning of the war there was scarcely a year in which they did not both promise and fail to perform.”


In 772 Charles led an army to Eresburg, a fortress on a hill. The Franks breached the defenses where they found a sacred grove. At its heart was Irminsul, a great tree used for pagan worship. Charles burned the holy tree and demanded that the captured submit to the one true God. The Franks conquered other towns, then began construction of a fortress at Paderborn, which later became one of Charles’ most important outposts and a later center of government. Then Charles left to fight the Lombards in Italy, at which point numerous Saxon tribes rose up and attacked the Franks.

In 775 King Charles returned and fought a handful of battles, which cowed the Saxons into swearing fealty to him again. Meanwhile at Lübbecke, a smaller Frankish army dispersed to forage for food. As they did a group of Saxons pretended to be part of their company and returned with them to camp. That night, when the Franks fell asleep, the Saxons slaughtered as many soldiers as they could before fleeing into the wilds. Charles was outraged and launched a punitive mission into Westphalia before retiring for the winter.

The following year the Saxons broke their oaths, took the fortress at Eresburg and marched on Syburg. The Royal Frankish Annals note that when the Saxons tried to set up siege equipment it did more damage to them than to the walls, which is both incredibly harsh and possibly true.

Charles then raced up to Worms and marched through Saxony, winning a major battle. This victory cowed the Saxons who pledged loyalty to Charles. But the Frankish King couldn’t trust the word of a pagan and so he had the Saxons, their wives and children baptized at the river Lippe. During this baptism they were required to renounce Odin, Thor and Saxnot, the latter being the deity of the Saxon people.

The next year, 777, Charles held his annual council of notables at Paderborn. All the Frankish lords assembled alongside all the Saxons, except for a man named Widikund. We know very little about Widikund’s origins, since most Germans were illiterate, and almost no written records survive. But according to the Frankish annals he was Charles’ fiercest opponent who led Saxon resistance for 8 years. Widikund was taking refugee in Denmark until King Charles left. When he did, the Saxon rode south and incited rebellion among the tribes, who rose up in 780.

In 782 Charles returned and decided that the Saxons could be made obedient and good if only they were turned into good Christians. By removing their pagan beliefs, Charles hoped to instill them with proper morals. Further, if the Saxons believed that the Catholic Church held power over their immortal soul, and if the Catholic Church was obedient to Charles…well you can see how this works. Thus, Charles issued the First Saxon Capitulary, a series of laws that enforced Christian observance. The first law condemned pagan idols and assumed the supremacy of Christian veneration. Violence against churches and churchmen were banned, as was cannibalism and human sacrifice. Anyone who refused baptism or ate meat during Lent was executed. Disobedience to a lord was forbidden. Tithing was enforced, that is giving 10% of one’s wealth to the church. Finally, all meetings between Saxons were banned unless they had the permission of a Frankish lord.

While Charles was administering his new laws, he sent an army led by a commander Adalgis northeast to deal with Slavs on the border. While en route Widikund amassed an army. When Adalgis heard about this he pursued Widikund with his elite cavalry. Along the way Adalgis met with Charles’ cousin Theodoric who had his own army. The two forces chased Widikund to the Süntel massif where his 5,000 men held up in a fort on the eastern bank of the river Weser. Theoderic set up camp on the western bank while Adalgis’ cavalry held a position on the Saxons’ eastern flank, trapping them.

Widikund knew he had to break out; otherwise his men would starve or Frankish reinforcements could arrive. With no other options he assembled his army just outside the fort’s eastern side for what should have been a desperate last stand. Then Adalgis’s pride led to disaster. He assumed that his cavalry could easily break his foes since they were on an even plain, which was perfect terrain for such a force. Instead of waiting for Theodoric, Adalgis ordered a charge. As the Franks charged they broke into a full sprint, with some horses overtaking others, breaking the lines. The Saxons were far better soldiers than Adalgis anticipated. As the horsemen approached, Saxons who had been hiding in the fort leapt onto the battlements and hurled missiles at the Franks. The Saxon phalanx then engulfed the Franks and utterly slaughtered them. Widikund and his men then slipped away before Theodoric could arrive. When king Charles heard about this he ordered the execution of 4,500 Saxons in retribution in what historians call the Massacre at Verden.

For the next three years Charles fought a brutal campaign against the rebellious Saxons, smashing their forces wherever he met them. In 785 the exhausted Saxons surrendered Widikund to Charles at his villa at Attigny. There Widikund and his fellows were baptized and accepted Charles as their godfather and lord, before disappearing from the historical record.

Saxony had peace for seven years, and Charles even went beyond Germania, into what is today western Poland, where he made the Slavs his vassals. But peace didn’t last, and events within Francia led to more rebellion. During this period Charles sought to cut down on corruption amongst the aristocracy and rationalize the tax system, a program which went over about as well as you’d think. The Frankish nobility grumbled but they couldn’t openly move against their king until 792. While Charles was fighting the Avars, a number of Franks rallied around his disinherited eldest son Pepin the Hunchback and plotted Charles’ assassination. The plot was betrayed and Charles condemned most of the conspirators to death, save his son who he had tonsured. While Charles was occupied with the attempted coup, the Avars and chaos in Italy, a number of Saxon tribes revolted. By now most Saxons had been brought to heel, and would rather join with Charles than fight against him. One of the last major Saxon armies marched against Charles’ Slavic vassals and were defeated.

Between 795 and 804 Charles engaged in a program of mass deportations. He forcibly rounded up tens of thousands of Saxons, divided them into small groups and resettled them in western Francia. These small groups were surrounded by Franks, adopted their language, law, customs and religion. It is very possible that Charles decided upon this strategy due to his diligent reading of Roman history. The Romans employed this same strategy against the Franks, who became one of the most important and loyal members of the empire, as we talked about in episode 31: The Long War: Rome and Francia.

By 804 Charles had finished his wars of conquest. Over a period of thirty-two years he had conquered northern Spain, half of Italy, Brittany, and Germania, while making vassals of nearly all the people on his eastern frontiers. While these conquests alone would have made him a legendary figure, what made Charles’ empire so much more impressive was that he incorporated each new territory into a Frankish system. The explosion in writing caused by his patronage of learning meant that civil administrators operated across the empire. They could tax efficiently, instill laws and coordinate with officials across hundreds of miles in a complex way. Institutions such as palaces, manors, councils, law courts and churches brought conquered peoples into a Frankish political system. Investments in infrastructure like roads, canals and forts meant that the army and civilians could travel more quickly and safely across a large territory. All of these innovations meant that Charles’ empire wouldn’t simply dissolve from below after his death as the various peoples threw off the Frankish yoke. Instead, the empire had to divide from above, and even after his grandchildren carved it up, the Carolingian realms still maintained many of the cultural, religious and political practices that Charles established.




Bernard S. Bachrach, Early Carolingian Warfare: Prelude to Empire, 2001.

Kelly DeVries and Robert D. Smith, Weapons and Warfare: An Illustrated History of their Impact, 2007.

Matthew Innes and Simon MacLean, The Carolingian World, 2011

The Bible, King James Version

Early Lives of Charlemagne by Eginhard and the Monk of St Gall, edited by Prof. A. J. Grant

Medieval Sourcebook: Charlemagne: Capitulary for Saxony 775-790, Translation by Fordham University

Royal Frankish Annals