It’s often said that prostitution is the world’s oldest profession. If that claim holds water, then the second‑oldest trade must be that of the soldier‑for‑hire. Mercenaries have peppered every battlefield for millennia, and even after national standing armies became the norm in the eighteenth century, the market for hired guns never vanished. In fact, the modern era has seen a surge of private military contractors, especially after the 2003 Iraq invasion. In late 2017, former Navy SEAL Erik Prince – founder of Blackwater – penned an editorial urging that the Afghan war could be won by swapping out thousands of U.S. troops for contractors[1]. The proposal never gained official traction, but it underscored how mercenary forces remain a hot topic in contemporary strategy.
10 Fascinating Stories of Legendary Mercenaries Past
1 5 Commando
When the Congo broke away from Belgian rule in 1960, the newborn nation spiraled into a chaotic mix of insurgent warfare and ethnic violence. The left‑leaning revolutionary Patrice Lumumba attempted to consolidate power, but the most formidable opposition came from the mineral‑rich State of Katanga. Its leader, Moïse Tshombe, a devout Christian with a pro‑European outlook, attracted the colony’s white minority, who feared the anti‑white pogroms that erupted after a mutiny in Stanleyville in 1960. By 1961, Katanga’s forces were locked in a fierce siege at Jadotville, where Irish UN troops faced stiff resistance from white settlers who had fled to the mineral‑rich enclave.
Three years later, the Simba rebellion—led by a band of young communists—swept through northeastern Congo, seizing roughly half of the country. The national army proved woefully ineffective, prompting Prime Minister Tshombe (who had survived Lumumba’s assassination in 1961) to hire roughly 300 mercenaries under the command of the infamous “Mad Mike” Hoare. Hoare, a veteran of the British Indian Army in World War II, later turned big‑game hunter and mercenary in South Africa.
Inspired by the historic Wild Geese, Hoare assembled 5 Commando, a unit of white mercenaries drawn largely from South African Boers. This force, alongside other mercenary groups, helped crush the Simba uprising by 1965. 5 Commando earned a reputation for meticulous documentation because several journalists—including South African Hans Germani—served with the unit, chronicling its battles against the Simbas.[11] The saga even leapt onto the silver screen in the 1978 action film The Wild Geese, for which Hoare acted as a technical advisor. Many veterans of Hoare’s outfit later fought in the Rhodesian Bush War and in the myriad conflicts that pitted apartheid South Africa against its neighbors.
2 The Landsknechts
The Landsknechts were the most controversial yet wildly successful mercenary corps of the Early Modern period, hailing almost exclusively from the Germanic states of the Holy Roman Empire. In the sixteenth century they earned a reputation for ferocity, shifting loyalties, and a penchant for pillage. Contemporary accounts even noted that Landsknecht soldiers would sometimes flip sides mid‑battle.
Emperor Maximilian I of the Holy Roman Empire created the Landsknechts as a direct response to the famed Swiss pikemen serving the French. He recruited robust men from Swabia, Alsace, Tyrol, and the Rhineland, granting them the freedom to dress flamboyantly—an exemption from strict clothing regulations that made them instantly recognizable on the field. Their armaments included the halberd (a poleaxe), the massive two‑handed zweihänder sword, and the early long‑gun known as the arquebus.
At the battles of Bicocca (1522) and Marignano (1515), the Landsknechts outmaneuvered the Swiss pikemen, employing tight squares of pikemen supported by halberdiers, firearms, and swords. They also pioneered the “forlorn hope” tactic, where daring swordsmen surged between opposing pikemen to sow chaos. By the time the Protestant Reformation rolled around, many Landsknechts had embraced Lutheranism, though they continued to serve Catholic patrons. Their lifestyle was infamous: they traveled with prostitutes, drank heavily, and were known to commit rape and pillage when pay was delayed. Their motto, coined by famed commander Georg von Frundsberg, summed up their ethos: “Many enemies, much honor.”
3 The Eagle Of Brittany
While John Hawkwood of the English White Company often steals the limelight, another medieval war‑lord—Breton knight Bertrand du Guesclin—earned the monikers “Eagle of Brittany” and “Black Dog of Broceliande.” Born in 1320, du Guesclin first saw action in the 1340s, fighting for the House of Blois against the House of Montfort during the War of Breton Succession. After a defeat at the Battle of Auray, he was captured by Anglo‑Breton forces and ransomed for an eye‑watering 100,000 francs.
Following his release, du Guesclin briefly left France to serve as a mercenary in Spain under Count Henry of Trastamara, the future King Henry II of Castile and León. He distinguished himself in the Castilian Civil War, where his “free company” helped secure victory at the Battle of Montiel in 1369. A year later, French King Charles V recalled du Guesclin to fight the English. In 1370, he was appointed Constable of France—the kingdom’s highest military office.
Du Guesclin’s tactics favored the Fabian strategy: avoiding large set‑piece battles in favor of swift, harassing skirmishes. Under his leadership, French troops and mercenary bands repeatedly outmaneuvered English forces, cementing his reputation as one of medieval Europe’s most cunning commanders.
4 The White Legion
Africa has long been a hotbed for mercenary activity, especially since the late nineteenth century. One of the more notorious units was the White Legion, which fought for Mobutu Sese Seko during the First Congo War. Roughly 200 Eastern European soldiers—mostly veterans of the former Yugoslav wars—formed the core of this private force.
The White Legion’s primary mission was to guard the strategic city of Kisangani. By 1997, it became evident that Mobutu’s regime was on the brink of collapse, and the Legion withdrew after a series of minor engagements. Though the unit played no decisive role in the war’s outcome, its presence highlighted the globalization of the mercenary trade. Many of its members had previously served under Bosnian Serb commander Ratko Mladic, infamously dubbed the “Butcher of Bosnia” for his wartime atrocities. In 2017, Mladic received a life sentence for war crimes.[8]
5 The Black Army
The Black Army was a largely mercenary force that propelled the Kingdom of Hungary from a peripheral realm to a dominant power in Christendom. Its founder, King Matthias Corvinus—dubbed the “Renaissance King” for his vast library, scientific curiosity, and shrewd statecraft—recognised the need for a professional fighting force to counter the expanding Ottoman threat.
To finance this army, Matthias imposed taxes on the Hungarian nobility, raising a 30,000‑strong mercenary corps drawn from Bohemia, Austria, Poland, Croatia, Serbia, Bavaria, and Switzerland. Until Matthias’s death in 1490, the Black Army reigned supreme in Central Europe, earning a reputation as the premier fighting force in the Balkans and Eastern Europe.
Despite its successes—including several decisive victories—the Black Army eventually declined due to fiscal reforms in the sixteenth century that stripped its funding. Notably, the army was among the first European forces to adopt firearms on a large scale, marking a pivotal shift in military technology.[7]
6 Swiss Mercenaries
Switzerland today is synonymous with neutrality, yet its soldiers have a storied past as some of Europe’s most feared mercenaries. The first documented Swiss mercenary companies appear in the thirteenth century, but their fame truly blossomed in the sixteenth century.
Swiss troops fought for King Louis XII of France during the Italian Wars and, from 1516 to 1793, served almost exclusively under the French crown through an unofficial agreement. Their elite units were the pikemen, who formed tight phalanxes wielding 6‑meter (20‑foot) spears. In 1386, a force of 1,200 Swiss pikemen routed a 6,000‑strong Holy Roman army invading Swiss lands. Later, at the 1444 Battle of St. Jakob an der Birs, the French under King Louis XI were repulsed by 1,200‑1,600 Swiss pikemen despite being outnumbered 15‑to‑1.[6]
Recognising their battlefield prowess, both France and Austria employed Swiss pikemen to great effect. They assisted Spanish and Holy Roman forces in capturing Milan in 1525. The Swiss reputation also earned them a place in the Vatican’s elite guard: the Swiss Guard, formally established in 1506, still protects the Pope today.
7 The Mercenary Revolt In Brazil
Mercenaries are notorious for fighting solely for pay, a trait that can lead to unruly conduct. This was starkly illustrated in 1828 when Irish and German mercenaries rose up against the Empire of Brazil—the very state that had hired them.
The unrest stemmed from the Cisalpine War between Brazil and the United Provinces. By July 1828, Brazil’s war fatigue peaked after a series of defeats. Frustrated that their contractual terms remained unmet, two battalions of Irish and German mercenaries seized control of a sizable portion of Rio de Janeiro.
Violent suppression followed: a coalition of 300 Brazilian troops, 300 French sailors, and 224 British Royal Marines crushed the rebellion, killing roughly 150 mercenaries. Surviving Irish soldiers were repatriated, while many Germans were dispatched to remote Brazilian provinces.
8 American Mercenaries In China
American adventurers have long been woven into China’s tapestry. Throughout the nineteenth century, missionaries, physicians, and teachers populated coastal hubs such as Shanghai, Tianjin, and Qingdao. Parallel to these civilian endeavors, a cadre of American mercenaries found employment with either the Qing Dynasty or the warlords who rose after the 1911–1912 Xinhai Revolution.
Among the most notable were Homer Lea and Philo McGiffin. Lea, a Colorado native, became fascinated with Chinese affairs after befriending Ng Poon Chew in Los Angeles’s Chinatown. He learned Cantonese, joined a secret society, and began training Chinese recruits while still based in California. In 1899, he enlisted with a force loyal to warlord K’ang Yu‑wei and remained in China until Empress Dowager Tz’u Hsi initiated reforms. Lea later befriended Sun Yat‑sen in Hong Kong, and his 1909 treatise, The Valor of Ignorance, predicted a Japanese assault on the Philippines and Hawaii.
McGiffin, hailing from Pennsylvania, failed to graduate from the U.S. Naval Academy due to poor exam scores. Undeterred, he sailed to Tianjin during the Tonkin War (1884‑1885) and volunteered for the Imperial Chinese Navy. After a stint as an instructor at the Chinese Naval Academy, he served aboard the battleship Chen Yuen during the 1894 Battle of the Yalu River. Though the Japanese fleet decimated its Chinese opponent, McGiffin’s vessel fought on for hours before finally succumbing.[4] The most celebrated American mercenaries in China were the “Flying Tigers,” a volunteer group that served under the Chinese Air Force between 1941 and 1942.
9 The Wild Geese
The Wild Geese, active in the seventeenth and eighteenth centuries, can be seen as the direct descendants of the ancient Celtic mercenaries who once roamed the Mediterranean. After the 1691 Treaty of Limerick—concluding the Williamite‑Jacobite War—Irish Jacobite General Patrick Sarsfield negotiated the departure of as many as 20,000 Irish Catholic troops onto French vessels, where they entered mercenary service across Europe.
These battle‑hardened soldiers quickly earned a reputation as elite light infantry, regarded as the finest on the continent. Irish mercenaries had already been serving Habsburg Spain since the 1580s, when the English crown shipped rebellious Catholics to fight for the Spanish, simultaneously quelling Irish unrest. Many of these Irish soldiers pledged allegiance to Spain, battling English and Dutch forces, later fighting against Napoleon and taking part in Mexico and South America during the height of the Spanish Empire.[3]
The Wild Geese cemented their martial prestige in France, serving in the Irish Brigade during the War of Spanish Succession, the War of Austrian Succession, and the Seven Years’ War. They also fought alongside Spanish‑French forces against the British during the 1781 siege of Pensacola, Florida.
10 The Celtic Mercenaries Of Egypt
Ancient chronicles make it clear that certain tribes have always been deemed war‑like. While the Western Roman Empire and later periods saw Germanic and Swiss warriors dominate the mercenary scene, the earliest sought‑after fighters were the Celtic peoples of Gaul, northern Italy, the Balkans, and the British Isles.
From the fourth century BC onward, Celtic tribes began raiding Mediterranean city‑states. In 390 BC, Celtic forces sacked an Etruscan settlement on the Tiber River, igniting a protracted feud with the Italian peninsula. This conflict climaxed on July 18, 387 BC, when a Gallic army led by Brennus crushed a Roman legion and plundered Rome, absconding with slaves, women, and treasure.
News of these fierce red‑ and blond‑haired warriors spread rapidly. Greek city‑states such as Syracuse and Sparta frequently hired Celtic mercenaries, and even the Carthaginian commander Hannibal incorporated Celts into his ranks during the Second Punic War.
Celtic mercenaries also fought far beyond Europe. Under the Greek‑origin Ptolemaic dynasty in Egypt, they were regularly recruited into the official army. Many hailed from Eastern European tribes and Galatia in central Anatolia (modern‑day Turkey). During Pharaoh Ptolemy III Euergetes’s reign, Celtic mercenaries played a pivotal role in conquering Syria and Judea, defeating the Seleucid Empire’s forces. Historian Polybius recorded that numerous Celtic soldiers settled in Egypt, marrying Greek or Egyptian women; their mixed‑heritage offspring were referred to by the Greeks as e pigovoi.