Mercenary armies

Mercenary armies are hired troops whose loyalty rests on wages rather than on a durable bond with the Prince, the State, or the community they defend. In the book’s analysis, they are not merely an imperfect military instrument but a structural danger: a ruler who entrusts his State to them cannot be securely established, because the soldiers and their commanders possess incentives that diverge from those of the government that employs them. Their apparent strength conceals dependence, opportunism, and an inability to bear the decisive risks of war.

Definition and Political Danger

Mercenary armies appear in the discussion of the forces available to every kind of Princedom. The principal alternatives are the Prince’s own subjects, mercenaries, auxiliaries, or combinations of these. The judgment is categorical: mercenaries and auxiliaries are useless and dangerous, while a State defended by mercenary troops can never be solidly or securely seated. Mercenaries are described as disunited, ambitious, insubordinate, treacherous, insolent toward friends, cowardly before enemies, and without either religious fear or human fidelity.

Their basic weakness is an absence of motive beyond payment. A hired soldier may remain in service while peace makes military employment easy, but when war demands endurance and the risk of death, the contract offers too little reason to sacrifice himself. The result is a reversal of the protection such troops are supposed to provide: in peace, the State is exposed to their plunder; in war, it is exposed to its enemies. When attacked, they are expected to bring defeat, and once war is declared they may simply abandon the field.

The book connects this military dependence directly to the condition of Italy. Its present ruin is attributed to the long reliance on mercenaries. These forces could display strength when opposed only to one another, but they revealed their true character as soon as foreign enemies appeared. That weakness allowed France to conquer Italy with striking ease, while the political rulers who had chosen such arms paid the penalty for their decision. The failure is therefore presented as a failure of princes, not as an unavoidable misfortune imposed by war.

Commanders and the Agency Problem

The danger becomes sharper when the mercenary captain is considered. If the captain is capable, he cannot safely be trusted, because his military power gives him the means to enlarge himself at the expense of his employer. He may overthrow the Prince who commands him, or undertake actions against other powers that serve his own ambition but contradict the Prince’s wishes. If the captain is incapable, the State faces ruin for the opposite reason: the army lacks the leadership needed to win.

This creates a trap in which both competence and incompetence are threatening. The employer needs an able commander, yet an able commander controls the force that the employer cannot safely control. The commander’s information, reputation, and armed following give him bargaining power, while the Prince bears the political consequences of his decisions. The same problem appears in the book’s later discussion of ministers: a servant who thinks more of himself than of his Prince cannot be trusted, because his office becomes an instrument for pursuing private ends. Mercenary command magnifies that ministerial problem by placing organized violence in the hands of an interested agent.

The recommended alternative is that a Prince command in person when arms must be employed, while a Republic should entrust command to one of its own citizens. An incapable commander can then be replaced; a capable one can be confined within proper legal limits. Princes and Republics that rely on their own arms are said to achieve the greatest success, whereas dependence on mercenaries produces loss. The contrast is institutional as well as military: national forces remain answerable to the political community, while hired commanders can convert delegated authority into independent power.

Historical Examples

The Carthaginians provide an ancient example of the danger. At the end of their first war with Rome, their hired troops nearly ruined them, even though those forces were commanded by Carthaginian citizens. The problem therefore did not disappear merely because the nominal commanders belonged to the polity; the hired army itself remained a destabilizing power whose interests could not be safely aligned with the State.

Thebes offers another warning. After the death of Epaminondas, the Thebans made Philip of Macedon captain of their army. Although he won a victory for them, he then deprived them of their liberty. Military success thus became the route to political subordination: the power invited to defend the community acquired the means to rule it.

The Milanese repeated the error after Duke Filippo died, hiring Francesco Sforza to conduct their war against the Venetians. After defeating the enemy at Caravaggio, Francesco Sforza joined with that enemy against the Milanese who had employed him. His victory did not secure Milanese independence; it gave the commander the leverage to turn against his own employers.

The conduct of Francesco Sforza’s father is presented as an even more direct demonstration of contractual unreliability. While serving Giovanna, Queen of Naples, he suddenly abandoned her without troops. To save her kingdom, she was forced to place herself under the protection of the King of Aragon. A ruler who relies on hired arms can therefore be compelled, at the moment of greatest danger, to seek protection from another power rather than command a force faithful to her own cause.

The apparent successes of Venice and Florence do not refute the argument. Florence was fortunate because several captains who might have dominated it were unsuccessful, checked by rivals, or drawn toward other ambitions. Giovanni Acuto’s fidelity was never tested because he did not win; had he been victorious, the Florentines would have been entirely in his hands. The Sforzas were restrained by the Bracceschi, while Francesco’s ambition focused on Milan and Braccio’s on the Church and the Kingdom of Naples. These circumstances limited the danger temporarily, but they did not make mercenary power safe in principle.

Paolo Vitelli illustrates the same risk in a more immediate form. Florence chose him as captain after he had risen from private life to the highest military renown. Had he succeeded in reducing Pisa, the Florentines would have been completely subject to his will. If they dismissed him, they risked his joining their enemies; if they retained him, they had to submit to him. A successful mercenary commander could therefore make his employer dependent on the very man whose authority the employer had created.

Italian Military Practice

The Venetian experience shows how reliance on hired forces marked a departure from an earlier and stronger political order. Venice conducted its affairs with glory and safety while subjects of every rank bore arms in its wars, before it turned its enterprises toward the mainland. Once it adopted the military customs of Italy and expanded its land territories, it became vulnerable to the power of captains.

The case of Carmagnola makes the contradiction visible. Venice first found him a valiant and skillful leader when, under his command, it defeated the Duke of Milan. Later, however, he appeared slack in carrying on the war. The Venetians concluded that further victories were unlikely, but fear of losing what they had already gained prevented them from simply dismissing him. To protect themselves against the commander they had employed, they were forced to put him to death.

After Carmagnola came captains such as Bartolommeo of Bergamo, Roberto of San Severino, and the Count of Pitigliano. Under these commanders, Venice’s principal danger was not the political domination that might follow victory but military defeat. At Vaila, it lost in a single day what had taken eight hundred years to acquire. The book’s economic contrast is severe: gains produced by mercenary arms are slow, late, and inconsiderable, while their losses are sudden and astonishing.

The rise of mercenary warfare in Italy is explained historically. As Imperial control was rejected and the temporal power of the Pope grew, Italy divided into separate States. Cities took up arms against nobles who had previously held them in subjection with Imperial support; the Church supported some of these struggles in pursuit of greater temporal authority; and private citizens became rulers in other cities. The Church and the Republics, lacking rulers and citizens accustomed to military command, began hiring foreigners. The institution grew from this political fragmentation rather than from a neutral search for military efficiency.

The service acquired its first great reputation from Alberigo of Conio in Romagna. His school produced, among others, Braccio and Sforza, who became arbiters of Italy, followed by the later captains whose employment coincided with the country’s humiliation. Through this succession of commanders, Italy was overrun by Charles, plundered by Louis, wasted by Ferdinand, and insulted by the Swiss. Mercenary armies thus form part of a chain linking military organization to foreign domination.

Tactics, Incentives, and Consequences

The mercenary captains’ first objective was to discredit infantry and magnify the value of their own followers. Because they possessed no territory of their own and depended on war for their livelihood, a small number of foot soldiers brought them little prestige, while a large infantry force was difficult for them to provide. They therefore favored cavalry, whose smaller retinue appeared more distinguished and was easier to maintain. The distortion was extreme: an army of twenty thousand might contain fewer than two thousand foot soldiers.

Their military rules were designed to reduce fatigue and danger. They avoided killing one another in battle, preferring to take prisoners who were later released without ransom. They would not attack a town by night, nor would defenders make a night sortie against a besieging army. Their camps lacked ramparts and trenches, and they conducted no winter campaigns. These practices protected the soldiers and commanders from the costs of warfare, but they also stripped war of the discipline, surprise, endurance, and lethal commitment required for real defense.

The consequence was not humane security but national weakness. By organizing war around the preservation of the hired force rather than the survival of the State, mercenary commanders turned military service into a protected profession detached from political responsibility. The book therefore treats their customs as one of the causes that brought Italy into servitude and contempt. The remedy is not merely to improve the contract or choose a more reputable captain, but to replace mercenary dependence with arms rooted in the Prince’s subjects or the Republic’s own citizens.