Throughout history, many mercenary groups and armies have played a decisive role in major wars, sometimes far surpassing their regular counterparts on the battlefield. While none of them survive today – as the development of modern warfare and weapons made them obsolete – they’re still remembered as some of the most successful fighting units ever deployed.
10. Genoese Crossbowmen
The Genoese crossbowmen were one of the most skilled and accomplished elite forces in medieval Europe. They were known for their expertise in naval warfare, and were considered better than any other archer unit on the continent. Their superiority came from the inherent advantage of their weapon – the crossbow could fire more than six shots per minute!
Formed in 1338, Genoese crossbowmen protected the Republic of Genoa and acted as mercenaries for various Italian city states and European monarchies. They were highly sought-after for their superior archery skills, and a typical unit was composed of the shooter and two assistants; one supporting the shield and the other handling a second bow to increase the rate of fire.
9. Winged Hussars
The Winged Hussars were an elite branch of the Polish military, originating in the 16th century as exiled Balkan mercenaries. Equipped with long lances and elaborate armor, the hussars adopted winged uniforms that served both as a terrifying tactic and protection, giving them their famous name.
It was a heavy shock cavalry renowned for its powerful charges, often impaling multiple enemies with a single lance. The Hussars won many battles over the years, including the famous Battle of Vienna in 1683, where they played a decisive role in the defeat of the Ottoman forces.
Despite their initial successes, however, the Hussars started losing their edge with the advent of firearms and new military formations. They couldn’t adapt to the changing battlefield, leading to their eventual decline. Their appearance and reputation as a successful Polish unit persisted, however, as they’re still an integral part of the combined history of the Polish-Lithuanian empire.
8. Landsknechte
Landsknechte were highly-skilled mercenaries originating in southern Germany, serving as heavily-armed pikemen and elite foot soldiers across Europe during the late 15th to early-16th centuries. While they were originally formed to fight in the armies of the Holy Roman Emperor, Maximilian I, their exceptional skill on the battlefield made them sought-after mercenaries across Europe. Additionally, their fabulous attire, which included oversized flat hats, colorful clothing, and billowing sleeves, sealed their reputation as one of the most well-dressed fighting units of all time.
The Landsknechte fought in a special pike-square formation, wielding weapons like the steel-tipped pike, the zweihänder (a broadsword), the katzbalger (a short sword), and the arquebus (an early matchlock musket). Their effectiveness with the formation and ability to adapt to Swiss pike tactics resulted in many military successes. Like other pre-gunpowder units of that time, however, changes in tactics and the emergence of firearms led to their eventual downfall.
7. Ten Thousand
The Ten Thousand were a Greek mercenary division that played a major role during the rebellion of Prince Cyrus of Persia in 401 BC. Made up of 10,000 Greek soldiers and accompanied by close to 100,000 native troops, Cyrus marched towards Babylon in a bid to overthrow his brother, and gain control of the Persian Empire. While he was defeated and killed in one of the battles, the Greek mercenaries managed to win on their own flank, distinguishing themselves as a successful unit of the campaign.
Before the fifth century BC, mercenaries were relatively scarce throughout the ancient-Greek region and were mainly employed by tyrants and kings, as city-states relied on citizen militias for their defense. It changed after the protracted conflict between Athens and Sparta, which militarized the region and led to many young men joining the armed forces, leading to a surge in the number of mercenaries across the Hellenic world, especially from the more impoverished areas like Thrace.
6. Condottieri
The condottieri were leaders of mercenary bands in Italy from the mid-14th to 16th centuries. Initially made of foreign fighters, these mercenary armies were hired by Italian states through contracts called condottas. Englishman Sir John Hawkwood and Italians like Muzio Attendolo Sforza and Braccio da Montone were some of the more renowned and militarily-successful condottieri. Sadly, at least for their clients, they were also known for their disorderly behavior and propensity for changing sides for quick personal gains.
The practice of hiring mercenaries by feudal lords and cities across Europe started in the 11th century, largely due to the increasing number of feuds. The condottieri, as leaders of these mercenary forces, usually had significant leverage over their clients, and were known to betray or even seize power from them. They also feature in Machiavelli’s works, who extensively talked about their actions and the tactical disadvantages that came with hiring them.
5. Gurkhas
The Gurkhas are fighting units that originated in the Nepalese town of Gorkha. While they fought and lost against the British in the Gurkha War of 1814-16, the British officers were impressed by their fighting skills. As a part of the peace treaty, many of these fighters joined the Company’s forces as mercenaries.
Over the years, the Gurkhas have proven their abilities in many successful British military operations, including both of the world wars. They could be recognized by their signature eighteen-inch knife called kukri. More than 19,000 have been killed in British service, though they have been hired by forces of other countries, too, like Singapore, Malaysia, and India. While the Gurkhas originally started out as mercenaries, there’s an ongoing debate around whether they should be designated as a regular part of the British Army due to their contributions.
4. Flying Tigers
The Flying Tigers were a renowned American volunteer group that operated during World War II. Formed in 1941, the group comprised volunteer pilots dispatched to the Chinese front to assist in the defense against Japan. Led by Lieutenant General Claire Lee Chennault, the Flying Tigers played an important role in the early stages of the war in the Pacific.
The Flying Tigers were known for their distinctive shark-faced fighter planes equipped with American-made Curtiss P-40 Warhawks. The group carried out multiple aerial combat missions against Japanese forces throughout the war, despite being outnumbered and facing superior enemy aircraft most of the time.
3. Varangian Guard
The Varangian Guard was an elite army corps and personal bodyguards to the Byzantine emperor, starting with Basil II in 988 AD. Originally made of Viking warriors known for their expertise with double-bladed battle-axes, the group eventually gained a reputation for their effectiveness in battle. One of their most notable recruits was Harald Hardrada, who’d later become the king of Norway from 1046 to 1066 AD.
The Guard – permanently stationed at the Great Palace of Constantinople – primarily served as shock troops and protectors to the Byzantine throne. They played a major role in the protection of the empire, and were famous for their distinctive weapons and armor, which included shields and the rhomphaia – a one-edged sword. Members of the guard were granted unique privileges, like the ability to seize gold from the imperial treasury upon the death of the emperor.
2. Grand Catalan Company
Catalan company, also called the Catalan Company of the East or the Grand Catalan Company, was one of the more-famous mercenary military groups in Europe around the 14th century. Composed mainly of soldiers from Catalonia and Aragon, the company operated as a private military in various conflicts in the eastern Mediterranean region.
The Catalan Company was formed in 1302 by veterans of the War of the Sicilian Vespers, which had left many of them unemployed. They initially served as a defense force for the Kingdom of Sicily, though soon transitioned into a powerful mercenary army of their own, seeking employment and contracts across the Mediterranean. Thanks to their reputation for discipline and tactics on the battlefield, the company remained in high demand throughout much of the middle ages.
While the Catalans won many military successes, their personal ambitions eventually led to tensions with their Byzantine employers. In 1311, they rebelled against the emperor, as they plundered the Duchy of Athens and established their own rule between 1311 and 1388.
1. Swiss Pikemen
After its independence from the Holy Roman Empire in the 14th century, the Swiss Confederacy established one of the most successful fighting forces in history. Swiss soldiers, known for their self-reliance and resilience in harsh conditions, initially used halberds and crossbows, and even swords, war clubs, and flails.
Swiss commanders were known for their understanding of the terrain, as they regularly won victories against vastly-superior forces by their innovative, terrain-specific tactics. The Battle of Arbedo in 1422 marked a turning point, as this was when they first adopted the pike as their primary weapon. The pike formations, fought in deep columns, proved highly effective in offense and defense, leading to many notable military victories. Their reputation extended far beyond their homeland, as Swiss mercenaries were sought-after by armies across Europe.