The Importance of Mercenaries in Medieval Warfare

Why mercenaries were used so often in medieval wars in Europe and a brief overlook of some of the elite mercenary troops from that time.

Mercenaries are viewed very negatively today but this was not always the case in the past. In medieval and early modern Europe they were an essential part of warfare and in many cases highly respected.

To understand why they were so important, we must understand the specific political and social conditions in Europe at the time, as well as the manner in which wars were fought.

Medieval Europe was very decentralized and its various kingdoms and rulers simply didn't have the means to train and maintain professional standing armies. Armies were organized on a campaign-to-campaign basis. Whenever the need arose, soldiers were recruited for a specific campaign and eventually the army was disbanded when the campaign was over or when money ran out.

The medieval West was dominated by a warrior class of nobility which was trained in the use of arms and also possessed expensive war horses and quality weapons and armor. But nobles were not enough for large scale warfare and armies had to be complimented by other troops.

The main problem here was that warfare was very elitist at the time in the sense that troops needed to be very skilled in order to be effective and proficient on the battlefield. Weapons like swords, bows, javelins, crossbows and pole weapons were hard to master and required great skills. Being an elite heavy cavalryman lancer, like medieval knights, or for example a proficient horse archer, required a lifetime of training. Equipment and weapons were also expensive. That meant that the number of skilled quality warriors in Europe was actually quite small.

Let's go through the kind of environments that could provide best warriors in medieval Europe, and which troops in particular achieved great renown as mercenaries.

Besides the nobility, the best trained troops were usually urban militias. Population of medieval cities was very warlike and took pride in their militias. Combat guilds were established where training was provided for citizens. Wealthy merchants who could afford good armor also served in such militias. Italian city states had good militias, especially the maritime republics which had to maintain a certain number of skilled crossbowmen on their galleys. The best known example of this are the Genoese crossbowmen. Good urban militias also existed elsewhere. Flemish militias proved their worth against French knights and won the Battle of the Golden Spurs in 1302. Pope Pius II commented in 1444 how skilled urban militias were in the Holy Roman Empire, “Not only every noble, but even every burgher in the guilds has an armoury in his house so as to appear equipped at every alarm. The skill of the citizens in the use of weapons is extraordinary.”

A 15th century depiction of the Genoese mercenaries at the Battle of Crécy in 1346.

There were also some rural commoners who would develop very good fighting skills in some circumstances. These were usually people from a landowning yeoman class, a middle class between nobility and serfs. These were men who could afford better weapons and become good at them. The famed English longbowmen are a perfect example of that. You also had cases of serfs rising through social ranks through fighting skills and becoming a special warrior class like the ministeriales knights in the Holy Roman Empire. These ministeriales entered military service of their lords and often performed administrative functions such as managing castles. Eventually they became a warrior class of its own and part of lower nobility. They evolved into Imperial knights and served the Emperor directly, becoming an essential part of Imperial army.

A specific type of environment which produced great warriors were various borderlands which experienced frequent fighting and raiding and where people needed to develop martial skills to survive. This often happened on the borders of Latin Christendom such as Iberia, the Balkans and the Baltics. The almogavars from the Crown of Aragon are a good example of that, as well as various types of light cavalry from the wars with the Ottomans such as the stradioti and the hussars. Another case of fierce borderland warriors were the border reivers on the Anglo-Scottish border. There were also certain parts of Europe where common people had more freedom and therefore more incentives to fight in wars and defend it, such as the Swiss or the Frisians.

But most common people in the Middle Ages would not make good soldiers and generally had no desire to fight in wars either. This was an age before modern nationalism and people would not identify with their country in the same way modern people would. Other than religion, there was no ideology that could mobilize a large number of people to fight. People served specific lords and generally not much would change if some other noblemen took their place. Most people simply didn't have a stake in various dynastic conflicts between nobility, other that they wanted these conflicts to end as soon as possible as they did not want their lands raided. The rare exceptions where you might see some “patriotic” spirit were the city republics and specific forms of state like the Old Swiss Confederacy. Such states might sometimes develop a more warlike spirit among population, and train their citizens in organized guilds, but were also constrained by their small size. Another factor was that even many well trained troops had little motivation to fight on campaigns far away from home. While urban militias could perform well when they had to defend their cities, sending them on campaigns to some distant lands was a different matter. Using unskilled and badly motivated peasant levies was therefore a last resort and used only to compliment the existing elite armies, not something a ruler would want to base his army on for a prolonged campaign.

So if you put all of this together, you can see why mercenaries became so important. The pool of trained warriors who were eager to fight in wars was simply very small in medieval Europe but demand was often high as wars broke out quite often, including prolonged conflicts that spanned over decades. People who were trained in the art of war and were veterans of various conflicts became highly sought after as mercenaries and could earn a lot of money by fighting all over the continent for whoever would pay them, as well as climb the social ranks this way. The story of John Hawkwood, the 14th century English mercenary and veteran of the Hundred Years’ War who ended up fighting in Italy for various lords, is probably the best example of that. He led the mercenary White Company and made a lot of money fighting in many Italian conflicts. He came from humble origins but achieved great fame and wealth as a soldier of fortune.

John Hawkwood at the Battle of Castagnaro in 1387. He achieved many great victories as the leader of the mercenary White Company, and earned a lot of wealth serving various Italian states.

Medieval mercenaries came from the ranks of the various elite and trained units from all over Europe that I described previously.

There were many knights from the ranks of nobility who served as mercenaries in conflicts in other lands. They were trained as warriors and serving as mercenaries was a great way for them to use their skills to earn some money. This was an especially great incentive for impoverished knights.

There were also many specific units that earned great reputation as mercenaries due to mastering a specific style of fighting that the major powers were deficient in. The Genoese crossbowmen were hired by France which lacked quality archers to deal with English longbowmen. During the wars against the Cathars in 13th century, the French hired experienced Basque mountaineers to help them conquer the Cathar fortresses which were on top of mountains and hard to reach. The English longbowmen who were veterans from the Hundred Years’ War ended up serving in Italy. Later on the Swiss pikemen would be highly sought after for their specific style of infantry fighting. Hussites also became highly valuable mercenaries because of their experience with handguns and war wagons. Various light cavalry troops from the Balkans gave versatility to Western armies that were used to rely only on heavy cavalry.

The use of such mercenaries meant that medieval armies in Europe were often very multi-ethnic, consisting of men from various races of Europe, and sometimes even with origins from outside of Europe. Holy Roman Emperor Frederick II settled Muslim Saracens on Italian mainland and recruited them as soldiers on his campaigns, using them as archers and light cavalry. Thousands of these Muslims fought in the Imperial army at Cortenuova in 1237 and at Parma in 1248. There was so many of them that the Emperor was mockingly referred to as “the Sultan” by his enemies. Hungarian kings used pagan Cumans, who had settled in Hungary, as horse archers and light cavalry. They contributed to joint Hungarian and Habsburg victory against the Bohemians at the Battle on the Marchfeld in 1278. Likewise, Christian knights sometimes served as mercenaries in Muslim armies. Henry of Castile “the Senator” led a contingent of Castilian knights to fight as mercenaries for Muslim emirs in North Africa in 13th century, earning a lot of wealth in the process.

The number of mercenaries kept increasing in next centuries. 14th century saw emergence of large mercenary free companies, particularly in France and Italy, as a result of prolonged wars there. These could number thousands of men and were often led by very ambitious and brutal men like Werner von Urslingen, a Swabian nobleman who commanded a large mercenary company in Italy, or Arnaud de Cervole “the Archpriest”, who served in the Hundred Years' War and eventually commanded his own mercenary company as well. Besides serving the lords who hired them, these men often also plundered and extorted the local population. This led to a massive problem as these mercenary companies turned to banditry during peace time. Men serving in them often had no intention to return to a peaceful life and wanted to continue to make a living by waging war. Marauding bands of unemployed mercenaries became a huge problem in France which saw the rise of so-called Tard-Venus bands after peace treaty was made with England in 1360. A royal army was sent to deal with them but was defeated. The best way to deal with marauding mercenaries was to try to send them to serve in another conflict in another country. Bertrand du Guesclin eventually employed a lot of free company mercenaries who were marauding in France for an expedition in Spain where they fought in the Castilian Civil War.

Being a warrior in the Middle Ages was not just a profession but a way of life. Wars gave birth to powerful violent warriors and once these wars ended, the rulers recognized that the men who distinguished themselves in war could become a problem during peace time. Such was the case with the elite almogavar warriors who served the Crown of Aragon. They were elite light infantrymen who originally fought as frontiersmen during the Reconquista, but eventually ended up fighting the French Angevins in the War of the Sicilian Vespers. After this war ended in 1302, they were organized into the Catalan Company and went to serve the Byzantine Empire. King Frederick III of Sicily had no desire to have such violent men in his land in peaceful times, as he was aware that they would cause problems.

The Catalan Company arrives in Constantinople in 1302.

The problem of marauding mercenary companies showed the obvious downside of large scale employment of mercenaries. In the 15th century the Kingdom of France tried to solve this problem by attempting to form their own infantry of “franc-archers” (free archers) recruited from the strongest and most capable peasants who were exempt from certain obligations in exchange for being part of a regular infantry force and trained in both archery and melee weapons. But this attempt of creating a standing army did not achieve the desired success. While the franc-archers could be useful for defending their land against bandits and as frontier troops to protect the borderlands, their effectiveness on military campaigns in foreign lands proved to be very bad, and they were not on the level of elite mercenaries. Such was the case in French campaigns in Flanders and Italy in late 15th century, where the franc-archers performed poorly. They were prone to desertion and capitulation, once again reflecting the main problem of levied infantries which was that they were simply not motivated to fight for causes that did not involve defending their own land. This is why the French ultimately preferred to rely on the elite Swiss mercenaries as their infantry for their aggressive campaigns in other countries.

Swiss mercenaries, also called the Reisläufer, rose to fame in 15th century as the Swiss achieved numerous impressive victories fighting for the Old Swiss Confederacy against external enemies. They pioneered infantry tactics with long pikes and halberds which proved to be very effective. They also became renowned for their warlike spirit and ruthless approach to war, not taking any prisoners. Another advantage was their military organization and recruitment.

The Old Swiss Confederacy was organized into cantons which had their own militias. The Swiss mercenaries could be hired from Swiss cantons as a ready-made army of local soldiers who spoke the same language and knew each other, making them more reliable in battles. This also meant that it was easier for a wealthy power like France to purchase Swiss mercenaries, as they only needed to approach the governments of the Swiss cantons rather than deal with the mercenaries directly. In return, mercenary service became a major source of wealth for the Old Swiss Confederacy and a great way for poor Swiss to earn money. Military became a source of great pride for the Swiss and besides money, they were also motivated to fight well on campaigns for foreign lords to preserve their reputation as the best warriors in Europe.

The Swiss pikemen developed a fierce reputation and became highly sought after as mercenaries.

In late 15th century large elite mercenary armies were employed by the rulers who were able to afford them. The mercenary Black Army used by the King of Hungary Matthias Corvinus proved to be extremely successful in the 1470s and the 1480s and enabled him to subdue much of Central Europe while also keeping his kingdom safe from the expanding Ottoman Empire. He used Bohemians trained in Hussite war wagon tactics for infantry, German knights as heavy cavalry, and Serbian hussars for light cavalry. This is another example of how elite mercenaries were able to cover deficiencies in European armies, making possible more versatile tactics for different types of warfare. Relying on heavy cavalry composed of nobility was not enough, armies also needed elite infantry and artillery to win wars. If there was a shortage of troops trained in particular type of warfare at home, rulers looked abroad to hire them as mercenaries.

But the main problem still remained similar as in the previous centuries. Despite the growing European states having increased capacity to hire large number of mercenaries, the number of elite mercenary units that were available over Europe was still limited. Swiss pikemen were highly sought but were also expensive and there was only so many of them. Furthermore, the Swiss refused to fight if fellow Swiss were present in the opposite army. Such was the case at Novara in 1500 when both France and Milan hired the Swiss mercenaries. The Swiss in the Milanese service mutinied and left the battle, leading to the capture of the Duke of Milan who had hired them.

For this reason the Holy Roman Emperor Maximilian started promoting a mercenary culture inside the Holy Roman Empire so that he would have access to infantry that could rival the Swiss. This is how the Landsknecht mercenaries were born. They imitated the Swiss tactics, in which they were trained by foreign instructors, rising to prominence in late 15th century. The Landsknechts, who were primarily German, provided a steady supply of mercenaries for Holy Roman Emperors, but also served other powers such as the French and the Spanish during the Italian Wars, eventually gaining enough experience in combat to be a formidable force on the battlefields. In this way the Holy Roman Emperors had their own mercenaries at hand, whenever they needed them for campaigns, without having to sustain them as a permanent standing army, for which they didn’t have the money. The Landsknecht mercenaries also crushed peasant rebellions.

The Italian Wars, a series of related conflicts in Italy which broke out in 1494 and lasted until 1559, gave the Swiss Reisläufer and German Landsknechts plenty of opportunities to serve and earn money as mercenaries. The Italian Wars popularized the pike and shot tactics in which infantry armed with pikes became crucial, and mercenaries specialized in this style of warfare were needed. The conflict eventually involved almost all major European powers fighting for influence in Italy, and they all hired either the Swiss or the Landsknechts at some point. The Swiss were even hired by the Pope in 1506 to serve as his guard which still exists to this day. This increased need for mercenaries also popularized the mercenary lifestyle. The Landsknechts evolved into a specific social group in the Holy Roman Empire, and their lifestyle became attractive to a number of adventurous men. Among mercenaries you could find men from all social classes. There were nobles and burghers from reputed families. But most were from poorer backgrounds. Many were outcasts, men with troubled violent past. Swiss mercenary Urs Graf, who became famous as an artist, was exiled from Basel in 1518 due to his violent behavior. His art depicts the mercenary lifestyle of the time, revolving around wars, violence, gambling and prostitutes. Mercenaries often spent their money just as quickly as they earned it and found it hard to settle in normal society once wars ended. This meant that many they kept returning to serve as mercenaries until it was possible.

In those times armies included a large number of camp followers which included women, children and various craftsmen. The number of camp followers often exceeded the number of actual soldiers. These camp followers provided various services and created a social environment for mercenary soldiers while they were detached from regular settled society. Mercenaries could travel with their families or concubines. They had their own rules and created a sort of parallel society. The Landsknecht mercenaries became famous for their distinct ostentatious fashion, as Emperor Maximilian made them exempt from sumptuary laws, allowing them to wear what they wanted. This lifestyle became very attractive to men who wanted to get away from regular society and join this type of dangerous but exciting life. But for the most part it was also a very brutal and harsh life.

The wars at the time were especially brutal. It was not just the brutality of battles itself but also the harsh life on campaigns due to long marches and lack of proper clothing and food. European rulers had minimal resources and had troubles with logistics and paying the troops. There was often not enough money to pay the mercenaries on campaign, leading to mutinies. In such situations, soldiers had to forage for food and steal to survive. This is why wars involved a lot of plunder at the time. This was also an important motivation for a lot of mercenaries and many joined for promises of loot they could obtain. A lot of money could be gained from sacking wealthy cities, which involved torturing rich citizens to reveal their treasures and holding them for ransom. There was a sort of unwritten rule that if a particular city resisted the besieging army, the soldiers were allowed three days of unrestricted looting of this city if they managed to conquer it. The Sack of Rome in 1527 was the most notorious example of mercenaries running wild and looting, but many other Italian cities were also brutally sacked.

This was also one of the main reasons why mercenaries became so hated by contemporary Italians such as Machiavelli, whose criticism of mercenaries is widely known today. However Machiavelli was wrong in his assessment of the military value of mercenaries. While mercenaries had obvious shortcomings, they were still by far the best units available at the time. In most cases they were actually very reliable, as money was the best possible motivation to fight in wars, and even if the states that hired the mercenaries ran out of money, these mercenaries could still be motivated by promises of loot and plunder. Elite mercenaries also needed to maintain their reputation. The Swiss were the best example of that and they performed a famous heroic last stand do defend the Pope during the Sack of Rome in 1527. Meanwhile Machiavelli's own attempts to create a good enough citizen militia failed.

It needs to be understood that people like Machiavelli were inspired more by ideology and their particular political vision than actual practical military needs. They idolized the ancient Roman Empire and wanted to model their armies according to Roman model. But the ancient Romans had the means to sustain a large standing army, contemporary early 16th century European states didn't. Mercenaries remained an important part of warfare in the early modern era even as armies became more professionalized.

To understand the importance of mercenaries in medieval warfare we therefore need to understand that warfare in those time was elitist and depended on skilled specialists who were in high demand. It was hard to train and motivate such troops to fight in campaigns, and powerful rulers preferred to use elite mercenaries whenever they could. A lot of elite mercenary units rose to prominence in the Middle Ages, and many mercenaries earned a lot of wealth and fame through warfare.