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Quentin Metsys, Moneychanger and his Wife, 1514 Conference



David A. Latzko
Department of Business and Economics
Wilkes University
Wilkes-Barre, PA 18766


The forces of supply and demand in the mercenary market as well as principal-agent problems and their solution are reviewed. The demand for ancient and medieval mercenaries, soldiers in eras when quality mattered more than quantity, primarily stemmed from their superiority to citizen soldiers. By 1700, quantity was the dominant factor and conscripts were now just as effective as mercenaries. Demand nearly vanished as it is less costly to raise a large, state-owned army of conscripts than to hire large numbers of mercenaries. State-owned armies also serve to reduce principle-agent conflicts.


Mercenaries have been a fixture in organized warfare since ancient times. They served Israel under both David and Solomon. Greek mercenaries served in Egypt prior to 500 BC. The army led by Hannibal across the Alps was entirely mercenary, and mercenary auxiliaries fought with the Roman legions. Mercenaries accompanied William the Conqueror on his invasion of England while mercenary crossbowmen fought at Crecy. The British hired mercenaries to serve during the American Revolutionary War and in Crimea. And, although the 1949 Geneva Convention regards mercenary activity as an international crime, 30,000 Russian mercenaries have fought in parts of the former Soviet Union and 2000 in Yugoslavia during the past few years (Yakov 1993).

A mercenary is a soldier in the service of a foreign power whose primary motivation is financial gain.1 A mercenary fights for a foreign nation for money (or for other inducements such as grants of land and admission to citizenship), not for ideology. Regulars, on the other hand, are citizens who have chosen military service as a career while conscripts are compelled by law to enter military service. The purposes of this paper are to review the economic forces that have been at work in the market for mercenaries and to explain why mercenary warfare has nearly disappeared since the 18th century.


Why do men become mercenaries? "For money, first of all," according to French mercenaries putting down a revolt in the Congo during the mid-1960's (Gleijeses 1994, p. 218). Indeed, whenever there was a general economic prosperity, the supply of mercenaries shrunk. The Greek city/states of the 5th century BC did not use mercenaries as the affluence of the era enabled most of the population to be employed in civilian pursuits (Parke 1933, p. 14). By the end of the Peloponnesian War in 404 BC, this no longer was true. The war had lasted nearly 30 years, and "the peace must have let loose upon the Mediterranean world many Greeks who had become accustomed to earning their livelihood by fighting" (Parke 1933, p. 18). The Greek agricultural sector was depressed throughout the 4th century, and the depression forced many peasants, who had been the backbone of the Greek armies, to abandon the farm to become mercenaries. Isocrates wrote in 380 BC of "many compelled through want of daily bread to serve as mercenaries" (Griffith 1968, p. 4). This increase in supply manifested itself in a steep drop in the wages of mercenaries. Between 400 and 350 BC the rate of pay for mercenaries fell from as many as eight to four obols per day (Griffith 1968, p. 297). In the late 4th century, subsistence income was two obols per day per person (Tarn 1925). This was what Athens paid to paupers who could not work. Skilled artisans received two drachmae a day when employed but employment was irregular. A worker who got more jobs than anyone else might make as much as 240 drachmae a year. This averages to four obols a day. Unskilled workers would average two obols a day. Thus, mercenaries in the late 4th century BC, at a time when there was a glut of mercenaries, received a wage equivalent to that of the most skilled worker. Mercenaries could also anticipate acquiring booty and a share of the proceeds of victory. For example, Alexander rewarded the Thessalian cavalry for its bravery at Ipsus by sending them in advance of his main army to occupy Damascus.

Mercenaries were often recruited from the economically backward areas of the ancient and medieval worlds. Rome recruited Numidians, Balearics, Gauls, Iberians, and Cretans during the Punic Wars. By the end of the 3rd century AD, German units formed the real strength of the Roman army (Delbruck 1975, vol. ii, p. 250). A large number of the mercenaries of the Middle Ages came from the mountainous regions on the fringes of Europe (Kiernan 1957, p. 70). Henry II and Richard I hired Welsh, Basques, Navarrese, and Galloway kerns. Most of the Genoese crossbowmen were drawn from Genoa's possessions: the Ligurian hills, Corsica, and Sardinia. Venice got many of its best mercenaries from Dalmatia.

One source of mercenaries during the medieval period was the younger sons of nobles who, having been disinherited by their fathers and unwilling or unable to enter the Church, took up professional soldiering. Many such mercenaries joined William on his invasion of England in the hopes of receiving land. This same motive existed for many Crusaders. As trade revived in the 13th century and towns rose in importance, feudal lords found themselves short of hard cash. As a result, feudal obligations from peasants to lords often became monetary payments rather than work. Serving as a mercenary was another method available to knights of acquiring cash (Gaier 1965). Like the ancient Greek mercenary, the medieval Italian mercenary received wages that were as high as most skilled workers earned. In Florence around 1400, the lowest paid manual workers received 20 to 25 florins a year while a skilled worker would get twice that. The average wage paid to a member of a three-man lance at that time was 40 florins a year (Mallett 1974, p. 136). This wage was only half what a three-man lance had received in the 14th century. The fall in the wage paid to mercenaries is likely a result of an increase in the supply of mercenaries due to the recovery of the population following the Black Death.

The basic wage of the mercenary German common foot soldier throughout the 16th century, four florins per month, compared favorably to that received by other workers. Day laborers in towns earned no more than two and a half florins per month while in the 1540's, a male agricultural worker received, besides food and lodging, three to ten and a half florins per year (Redlich 1964 vol. i, pp. 122, 127). Mercenaries could, of course, supplement their income by looting. By contract, they were permitted to keep harnesses, armor, and other movable objects. During the mid-17th century, for example, at a time when a skilled worker in Germany might possess wealth of 100 florins, a soldier returned from his very first campaign with booty worth 200 florins (Redlich 1956, p. 54). Some soldiers accumulated 8,000 to 20,000 talers by looting (Redlich 1964, vol. i, p. 496). Mercenaries could also ransom prisoners of war.2 Around 1600, it was fair to require as ransom the annual income of the prisoner's property or his annual pay if he did not possess property (Redlich 1956, p. 33).

Changes in the supply of ancient and medieval mercenaries then are traceable to changes in the attractiveness of alternative employments. Economic prosperity decreased the supply of mercenaries since there were many well-paying, less hazardous civilian jobs available; the supply of mercenaries swelled in times of economic hardship as there were fewer alternatives. Mercenary wages were responsive to shifts in supply, but ancient and medieval mercenaries consistently received wages comparable to that of very skilled civilian labor. Since successful soldiers had to have been quite skilled themselves, the compensating wage differential received by ancient and medieval mercenaries existed in the opportunities for plundering.


"Military economies of scale exist if an increase of x% in all inputs increases an army's destructive capability by more than x%" (Latzko 1993, p. 482). Economies of scale did not exist in ancient and medieval combat. Only the front ranks were able to combat the opposing force so that as long as the lines remained unbroken the number of men actually wielding their weapons on each side at any given instant was roughly equal. Large numbers of soldiers did not provide an army with a disproportionate advantage in the ability to inflict casualties. One man would find himself opposed to one man so that ancient and medieval battles, in essence, consisted of a series of individual duels in which combat ability was the decisive factor. Assuming that both armies were equally skilled, a larger army would defeat a smaller one but the armies could expect to suffer similar casualties. A small, highly skilled army could defeat a larger yet less skilled army. There existed, therefore, positive returns to quality and skill but not to scale in ancient and medieval combat.

The fact that the quality and skill of soldiers mattered much more than sheer numbers in ancient and medieval combat created the demand for mercenaries. Specializing in warfare made the mercenary a more effective fighter than citizen soldiers. By the middle of the 4th century BC professional armies outclassed the citizen hoplites (Parke 1933, p. 113). The medieval Florentine city militia also had shown itself to be inferior to mercenary armies. It had lost to smaller forces at Montaperti in 1260, Incisa in 1312, and Montecatino in 1315.3 Consequently, Florence began to employ mercenaries. By the campaign in the spring of 1342, the Florentine army contained 2,000 mounted mercenaries and only 40 citizen cavalry (Bayley 1961, p. 15). Venice also created a standing army of mercenaries as did all the other Italian city/states. This was the condottieri system which Mallett (1974, pp. 11-12) argues developed primarily for military reasons. The problem was that the bulk of the city militia was infantry and was unable to withstand a heavy cavalry charge. Mercenary infantry, however, could develop the cohesiveness to withstand such a charge through long service together. There was also increasing specialization in the military. The crossbow, for example, led to heavier plate armor which was costly and physically demanding to wear. Mercenaries were also likely to have kept up with technical progress in military matters (Kiernan 1957, p. 69). All this widened the gap between the citizen and professional soldier and made it necessary to hire mercenaries.

The demand for mercenaries in the ancient and medieval periods was not just a result of their military superiority. There was an economic advantage as well. Since professional soldiers possessed a comparative advantage in warfare, the use of mercenary armies rather than town militias freed citizens to pursue their own avenues of comparative advantage. After the plague struck Athens during the Peloponnesian War "the remaining citizens in business, on the farm, and in industry were even more indispensable than otherwise, and the number easily to be spared smaller, so that the number of mercenaries was certainly unusually large" (Delbruck 1975, vol. i, p. 51).

There were tactical military advantages as well to employing mercenaries. Jones (1987) stresses that the combination of weapons systems employed was often the determining factor in ancient and medieval battles. The use of professional soldiers enabled states to hire the force composition necessary for the campaign. Darius hired Greek mercenaries to serve as heavy infantry against Alexander and his outstanding Macedonian phalanx because Persia did not possess effective heavy infantry. The Greek city/states hired light infantry mercenaries to complement their heavy infantry hoplites. Richard the Lion-Hearted employed crossbowmen as a defense against Moslem horse archers.

The best mercenaries of the 15th century were the Swiss. Their mobile pike-armed infantry squares were the dominant weapon system of the period.

"A nation of armed peasants, afflicted with the chronic overpopulation of the barren uplands, numerous enough to form massive columns of pikemen, they acquired by incessant practice the extraordinary perfection of skill and discipline demanded by their system of warfare, and they did this at home in their valleys, at no cost to their employers" (Kiernan 1957, p. 70).
The development of the Swiss tactical infantry made it imperative for states to organize the same kind of forces if they wished to survive (Redlich 1964, vol. i, p. 3). Feudal states lacked the administrative structure for the large-scale military organization required by this development, so they turned to the military entrepreneur. Cities contracted with a mercenary captain to supply a certain quantity and type of soldier. Hiring mercenary companies was more efficient than hiring individuals since they were easier to hire and more effective fighters because of their experience of fighting together.4

Labor was scarce in 14th century Italy as a result of the plague. The population of Florence fell from approximately 95,000 in 1300 to 55,000 in 1400 and that of Pistoia fell from about 11,000 to 4000 over the same period (Cipolla 1980, p. 302). As a result of this labor shortage, cities would have had capital intensive militaries, for example, town walls and fortifications, which, consequently, would have been primarily defensive. The employment of mercenaries substituted military labor for capital and enabled cities to pursue offensive campaigns.

Longer campaigns provided another impetus to the demand for mercenaries. Citizen hoplites were not suited to long wars. They needed to return to their fields to harvest the crops in the fall and to plant in the spring.

"Such troops as the Greek mercenaries became could be used to garrison strongholds or fortified positions, for they could be continuously employed, as citizen troops could not be. And, having no homes, they were not always longing to return to them. And through the winter they could earn their retaining fee, while citizen troops were accustomed to fight only in the good season of the year" (Adcock 1957, p. 22).
The same problem existed for medieval rulers. By the end of the Middle Ages wars were usually not finished within the period in which a knight was bound to serve.5 Mercenaries also have the advantage over a permanent standing army of being able to be dismissed at the end of the campaign.

The replacement in the ancient Greek world of democratic governments by tyrants contributed to the effective demand for mercenaries. Cities could hire a large number of mercenaries only when they were ruled by a tyrant because the tyrant could raise the necessary money by confiscating the property of his political opponents (Griffith 1968, p. 3). This avenue was unavailable to constitutional governments. The wars of the Successors created an upsurge in the demand for mercenaries so that by 200 BC the rate of pay for mercenaries had increased to nine obols per day (Griffith 1968, p. 303).

Despots have often surrounded themselves with bodyguards of foreign mercenaries. For example, the Byzantine emperors had their Varangians, the French kings had Scots and later their Swiss Guard, Napoleon and his Poles, and Franco had his Moors (Kiernan 1957, p. 68). Foreigners make more reliable and loyal bodyguards since they are in a foreign land amidst a hostile population and totally dependent upon the despot. Mercenaries were also ideal for dealing with rebellious subjects since local troops may be have been unreliable. The demand for mercenaries in Norman England was fueled by the disloyalty of feudal vassals who would normally supply troops. "Deprived of many of their chief feudal assistants, the Anglo-Norman rulers were forced to hire soldiers in their bid to remain on the English throne" (Schlight 1968, p. 24).6 And, in anticipation of a civil war erupting out of the National Assembly, Louis XVI posted foreign mercenaries at key points in and around Paris.

At times there was a sort of Say's Law at work in the market for mercenaries: the mere existence of a supply of mercenaries called forth a demand for their services. The government of medieval Florence, as an example, was under considerable pressure to employ mercenaries just because there was an available supply. It believed that it had to hire them before it's rivals, Milan and Pisa, did. And, since mercenaries were necessary for engaging in an offensive campaign, hiring mercenaries could remove military operations from Florentine territory. Also, unemployed mercenaries would usually appear around harvest time either to pillage the countryside or to be paid for sparing it (Bayley 1961, p. 53). Thus, unemployed mercenaries could create for themselves the artificial conditions of war by becoming outlaws. Siena, in northern Italy, endured at least 37 separate mercenary incursions between 1342 and 1399 (Caferro 1994). To deal with the threat the commune often paid a bribe to the mercenary company.7 But, Sienese authorities frequently hired mercenaries of their own to defend the town.

In sum, the demand for mercenaries in the ancient and medieval periods principally stemmed from their military advantages. Mercenaries had a comparative advantage in violence acquired by their specialization in warfare. Professional soldiers simply outclassed civilian militias at a time when skill was the predominant influence on the outcome of battles. Use of mercenaries also enabled commanders to employ the force composition necessary for the campaign, to pursue an offensive campaign, and to hire soldiers for its duration. Mercenaries were also more reliable than potentially rebellious subjects. Other factors including the development of public finance and competition for their services fueled the demand for mercenaries.


An essential feature of the mercenary market has been differences in the aims of the mercenaries and their employers. "The state wanted quick and inexpensive victories; the condottieri wanted to make their living and save their skins" (Mallett 1974, pp. 101-102). This was especially the case in medieval Italy where, rather than serving as auxiliaries as in ancient and medieval warfare, mercenaries, led by a military enterpriser, composed the bulk of the armed forces. While the chess game nature of condottieri warfare is undoubtedly exaggerated, unnecessarily prolonged campaigns, sit-down strikes, and threats to retire during a crisis were not unknown. In 1362, for example, Florentine mercenaries besieging the town of Peccioli demanded double pay. When the government refused, three mercenary captains with 1000 troops withdrew from Florentine service (Bayley 1961, p. 12). During the campaign to regain possession of Pisa during the 1500's, French mercenaries in the employ of Florence "refused to advance against the city, complained about their pay and their food, mutinied, and disappeared from the camp" (Gilbert 1986, p. 11).8 Earlier, Memnon of Rhodes, the captain of the Greek mercenaries in the service of Persia at the battle of Granicus, had recommended a scorched earth defense against Alexander. The Persian satraps rejected his advice, in part, "because they had a suspicion that Memnon was deliberately contriving to prolong the war" (Arrian book I, ch. 12 1942, vol. ii, p. 418).

The cost to the employer of fielding a mercenary army was limited to the wages paid. They did not even bear the costs of supporting the widow and children of a mercenary killed in action. While their employers sought a short, decisive campaign in order to achieve their objectives at as small a wage cost as possible, mercenaries preferred to achieve the objectives with the least effort and risk of loss of life. Dead mercenaries reduced the labor force of the military enterpriser, and there was prestige and more money in commanding a large army. Therefore, mercenaries tended to fight wars of attrition to conserve soldiers and to lengthen the campaign so as to draw wages for a longer period of time. Consequently, wars were longer than necessary from the principle's perspective.

States did attempt to monitor the activities of their mercenaries. Medieval Italian governments appointed provveditori or civilian commissaries to accompany the army in the field. They passed on instructions from the government, sent back reports on the progress of the war, and gave advice to the commanders. There are reports of clashes between the commissaries and the condottieri, but more typical are the close personal links between some of the Venetian nobles who acted as provveditori and some of the leading condottieri, "sometimes too close for the peace of mind of the Venetian government. The reports of these civilians led more often to rewards for soldiers than to admonitions and executions" (Mallett 1974, pp. 89-90).

Governments resorted to the use of rewards such as cash bonuses, gifts, and pensions and penalties such as fines, dismissal, and execution to induce desirable behavior on the part of their mercenaries. Mercenaries earned bonuses for decisive victories. For example, Florence gave double pay for a month if an enemy force of at least 500 cavalry was driven from the field of battle (Bayley 1961, p. 13). If the mercenary captain was unsuccessful, though, he risked having his regiment taken away. Any error could lead to punishment with or without trial. Two examples: first, the troops of Paolo Vitelli, one of the Florentine condottieri, had breached the walls of Pisa, but Vitelli hesitated to order his troops to advance and the opportunity was lost. "Vitelli's exaggerated caution raised the suspicion of treason. He was disposed, brought to Florence, imprisoned, and finally decapitated" (Gilbert 1986, p. 11). Second, proven cowardice in the defense of fortresses was punished by decapitation during the Thirty Years' War (Redlich 1964, vol. i, p. 387) while rewards for great achievements usually took the form of grants of real property in conquered areas. "Of course, the permanence of possession so acquired depended on the ultimate success of the party to which the military enterpriser was attached" (Redlich 1964, vol. i, p. 392) thereby more closely aligning the interests of the mercenary captain and his employer.

The contracts between employer and mercenary, though, were not structured in a way that created strong marginal incentives. In medieval Italy, the first clause in the contract between the condottiere and his employer specified the number of troops to be provided. The state insisted upon inspections in the field to ensure that the army was the contracted size. The condottieri resented these inspections because they preferred to postpone making up any losses until they returned to winter quarters. "This was not just in order to pocket the money due to missing men themselves, but in order to be able to buy horses and equipment at more stable prices and recruit at greater leisure" (Mallett 1974, p. 99). The contract, thus, gave the military enterpriser a material interest in avoiding battle and conserving his forces.

The second clause stipulated the duration of the contract. The typical contract during the 14th century was for two or three months' service. The assumption was that military operations would cease during the fall season.

"The contract at short term, which enabled the city to drop incapable or lukewarm servants without undue delay, was naturally unpopular with the condottieri. They retaliated by slackening the tempo of their operations when their brief contract was approaching its term" (Bayley 1961, p. 14).
During the 15th century, six month contracts with an option of an additional six months were the norm. By mid century, "it was accepted that condottieri were in permanent service" (Mallett 1974, p. 83). Permanent service more closely aligned the interests of employer and employee thereby attenuating agency costs. But, there were still problems with mercenaries assuming government power and with roving bands of plundering, unemployed mercenaries. Such principle-agent problems could only be eliminated by forming a state-owned army of conscripts. That, though, required a technological development which eliminated the combat advantage enjoyed by professional soldiers.


The economic growth of the 18th and succeeding centuries reduced the supply of mercenaries. The demand for mercenaries fell even more as nations began to form professional standing or conscript armies. Consequently, the wages paid to mercenaries dropped. The foot soldier of the 18th century received pitifully low wages. In the era of Frederick William I, a Prussian infantryman received eight groschens for five days plus free clothing and shelter while a Brandenburg clothmaker earned two to three groschens per day (Redlich 1964, vol. ii, p. 246).

Combat skill mattered more than numbers up through the 16th century. The decline of mercenary warfare coincided with the emergence of large armies as the scale of warfare began to increase in order to take advantage of the emergence of military economies of scale on the battlefield. Firearms were responsible for the introduction of these scale economies onto the battlefield. The major advantage the firearm possessed over both the crossbow and the longbow was the length of training necessary to become proficient in using the weapon. The bows required years of training. But, since aiming was not a factor in hand gun training an individual could become an effective musketeer after a fairly short period of training (O'Connell 1989, p. 111). The firearm was a less costly weapon system than either the crossbow or the longbow and just as effective on a battlefield full of massed infantry formations.

When every soldier is able to fire on every other soldier, an army's destructive capability increases by the square of its size (Lanchester 1916). Military economies of scale will then exist as an army twice the size of another possesses four times the destructive capability. Missile weapons enable two or more soldiers to simultaneously attack a single enemy soldier. Unlike the bow and arrow, the musket was capable of piercing personal armor at a distance of 80 meters. Thus, unlike the archer, the musketeer was able to kill any enemy soldier within range on the battlefield. The use of muskets and artillery involved more than the front ranks alone, and the linear formations devised by Maurice of Orange allowed a greater proportion of an army to fire on the opposition at a given moment. As a result, the numerically inferior force finds itself under much heavier fire than it is able to return; the concentration of numbers gives a superiority in the number of active combatants. By 1600, musketeers had driven all but the pikeman from the battlefield. The socket bayonet, in universal use by 1700, rendered the pike redundant (Jones 1987, p. 268). By 1700 then, significant economies of scale were available on the battlefield (Latzko 1993, p. 482). Nations began to field larger armies to capture these scale economies. "The rise in combatants is obvious when one compares battles like Pavia (1525) and Nieuwpoort (1600), with 10,000 combatants on either side, and a battle like Malplaquet (1709), with 200,000 men involved" (Parker 1976, p. 207).

Changes in the art of warfare gave an enhanced advantage to the army with the numerical superiority. Large numbers of soldiers could be more readily acquired by conscription than by hiring mercenaries as mercenaries are difficult to recruit in large numbers. Furthermore, drilling of conscripts made them as effective as mercenaries were. Drilling also reduced the opportunity costs of fielding a conscript army. Drilling could turn almost anyone into an effective musket-armed soldier and enabled states to use people who were unproductive in other spheres (McNeill 1982, p. 137). Sweden adopted a scheme of universal conscription in the early 1600's (Parker 1988, p. 52), and Prussia began forced recruiting in 1688 (Shanahan 1966, p. 37). As early as 1704, the British Parliament provided for the forced impressment of vagabonds into the army (Graham 1971, p. 15). Universal conscription was adopted by the French in 1778 (Elting 1988, p. 20).

The size of the Austrian army increased by 300 percent between 1690 and 1778 and the size of the British army increased by 25 percent over the same period; between 1710 and 1756, the French army grew by 32 percent, the Russian army by 50 percent, and the Prussian army by 267 percent (Childs 1982, p. 42). Nations unable to raise large armies were suddenly at a distinct disadvantage. The king of Poland had been able to field an army of 30,000 men to lift the siege of Vienna in 1683 (Halecki 1956, p. 170), but by 1756 the Polish army numbered a mere 16,837 men (Childs 1982, p. 42). Less than 40 years later, Poland ceased to exist. Changes in military technology had increased the optimal size of an army. It was too costly to hire mercenaries in sufficient numbers to take advantage of the enhanced advantage of superior numbers so the demand for mercenaries fell dramatically. The last great battle of rival mercenary armies occurred in 1837 between the French and Carlist foreign legions (Mockler 1987, p. 22).


This paper has stressed the importance of economic factors in the market for mercenaries. Non-economic factors appear to have a strong influence on the supply side of the modern mercenary market. Perlstein (1988, p. 203) Interviewed a number of American mercenaries:

"All became mercenaries for similar reasons. The desire for adventure and excitement, the lure of money and the cause was believed worth fighting for--were the three most common reasons given. The media and political critics stress the monetary motivation of the mercenary, but the interviews showed that money was not the main reason. Adventure and the political cause emerged as the primary motivations."
Which isn't to say that the remuneration is not adequate. Although the starting pay in the French Foreign Legion is just $300 a month (Skari 1996), the CIA hired French mercenaries for $3500 a month in 1975 to fight in Angola (Mockler 1987, p. 168). Mercenaries participating in a failed 1977 coup in Benin received $2000 a month (Mockler 1987, p. 242) while those serving with the Rhodesian army during the late 1970's received $800 up to $3000 per month as the civil war intensified (Mockler 1987, p. 270). Looting opportunities are also still available. Mockler (1987, pp. 71-72) describes how mercenaries in the Congo in 1964-65 would blow up safes in banks, businesses, and private houses after they had liberated a town. Two South Africans, for example, found $65,000 in the safe of a private house during the sack of Stanleyville.

The modern demand for mercenaries has three sources: anti-guerrilla operations in Africa since the 1960's, coup attempts in Africa and islands in the Indian Ocean and Caribbean Sea, and irregular campaigns in Africa, Bosnia, and parts of the former Soviet Union. Mercenaries are now in the employ of those unable or unwilling to raise an army by conscription. Illegitimate forces, for one, have lately resorted to mercenaries to either make up entirely or augment their numbers. Mercenaries have found employment in coup attempts in Benin (1977), the Comores (1978), and in the Seychelles (1981), These small bands of mercenaries, in each case numbering less than 100, served as private armies. Anti-government forces in Bosnia and parts of the former Soviet Union have also employed mercenaries. Their employers were following the example of Moise Tshombe, leader of the Congolese breakaway republic of Katanga. 11 days after the Congo received its independence in 1960, Katanga seceded. Faced with forming the new army of a new state, Tshombe hired mercenary troops. "Recruitment centres were opened in Southern Rhodesia ... quietly at first, with discreet advertisements in the local newspapers" (Mockler 1987, p. 41).

The United States used mostly South African and Rhodesian mercenaries to put down the Simba revolt in the Congo during 1964-65. It was politically impossible for the U.S. to send its own troops while "no European or African government was willing to send its troops, and Washington knew it" Gleijeses 1994, p. 215). The U.S. later unsuccessfully used mercenaries during the Angolan civil war (Gleijeses 1994, p. 237). The advantage of hiring mercenaries in such situations is that it reduces overt Western involvement.


This paper has reviewed principle-agent problems as well as the forces of supply and demand in the market for mercenaries. When armies were led by military entrepreneurs their employers often suspected that their mercenary leaders deliberately avoided battles and casualties and that they prolonged a war to continue their employment, so they had in place a system of rewards and sanctions and monitoring that was able to reduce but not eliminate opportunism. Through the ancient and medieval periods, general economic conditions noticeably influenced the supply of mercenaries. The primary current supply of mercenaries is former members of the South African and Soviet armed forces, two militaries thrown into chaos by recent political events. The demand for mercenaries stemmed from several military advantages. Most significantly, this paper has argued, in an era when the art of war was such that the quality of soldiers mattered more than quantity, mercenaries were far superior to citizen soldiers. With the widespread adoption by 1700 of effective firearms and the socket bayonet, quantity became the dominant factor in determining an army's capability and conscripts were now just as effective as professional soldiers. The demand for mercenaries nearly vanished as it is more feasible to raise a large, state-owned army of conscripts than to hire large numbers of mercenaries. State-owned armies also serve to reduce principle-agent problems. In the modern era, only those entities unable to raise an army through conscription have a demand for mercenaries.


1. Brown (1989, p. 38) disputes the distinction between true personal followers and mercenaries based on the criteria that the latter "drew on his lord's purse rather than occupied some of his lands."

2. Allmand (1965) describes the sources of income of English soldiers during the Hundred Years' War.

3. Waley (1968) disputes this characterization of the Florentine militia. The Florentines defeated a mercenary army employed by Siena in the war of 1229-34 and, thus, demonstrated they were able to fight and win a long campaign.

4. See Redlich (1964) and Potter (1996) for descriptions of the role of the military entrepreneur in the market for German mercenaries in the 1500's and 1600's.

5. The development of a system of public finance was necessary to make this demand effective. The combination of mercenaries and regular taxation enabled states to raise larger armies and to keep them in the field for longer than before since such armies are unhindered by feudal restrictions on time and place. Harris (1975) and Miller (1975) describe the emergence of public finance in England during the Hundred Years' War.

6. Prestwich (1954) emphasizes the importance of mercenaries in England following the Conquest.

7. For example, the Ten Thousand attempted to raise money by blackmailing Heraclea (Xenophon book VI, ch. 2 1942, vol. ii, pp. 348-349). Similar bribes were extorted by mercenary armies during the Thirty Years' War. Called the Brandschatzung, it amounted to a payment for protection from looting and burning. The commander estimated the amount of damage the property owners would suffer if the town, village, or monastery were burned and offered to leave the property unharmed for a payment smaller than the estimated damage. See Redlich (1959).

8. It was experiences like this that shaped Machiavelli's opinion that "mercenaries ... are useless and dangerous, and if any one supports his state by the arms of mercenaries, he will never stand firm or sure, as they are disunited, ambitious, without discipline, faithless, bold amongst friends, cowardly amongst enemies, they have no fear of God, and keep no faith with men" (Machiavelli 1952, p. 80).


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David A. Latzko
Business and Economics Division
Pennsylvania State University, York Campus
office: 13 Main Classroom Building
phone: (717) 771-4115
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