Auxiliary troops

Auxiliary troops are forces sent by another potentate at a prince’s request to help defend or enlarge his state. In the political argument surrounding them, they represent a particularly perilous form of dependence: unlike national arms, they do not arise from the ruler’s own subjects, and unlike mercenary companies, they arrive already organized under officers who remain outside his control. Their immediate military usefulness therefore conceals a transfer of power. The prince who summons them may win the battle for which he called them, yet emerge from that victory unable to command the force that made it possible.

Definition and Strategic Danger

Auxiliary troops belong to the fourfold classification of military forces available to a prince: his own subjects, mercenaries, auxiliaries, or a mixture of these. Mercenaries are hired soldiers, while auxiliaries are troops supplied by a foreign ruler whom the prince summons to his aid. The distinction is decisive because auxiliaries possess a coherent organization before they enter the prince’s service. They are united and remain wholly under the authority of their own officers, rather than being separate companies raised and paid directly by the ruler who needs them.

This structure creates an extreme dependence. If the auxiliaries are defeated, the prince is ruined along with them; if they are victorious, he becomes their prisoner in political terms. Their success leaves the state indebted to a foreign military power whose commander may possess the means to dictate the settlement, while their failure removes the very protection on which the prince has staked his position. The danger is thus not simply that foreign soldiers may behave badly. It is that their military effectiveness gives them leverage over the state they have supposedly come to save.

The contrast with mercenary troops clarifies the argument. Mercenaries are also unreliable, but their danger usually appears as inertness, cowardice, or desertion. Because they consist of separate companies raised and paid by the prince, the captain placed over them cannot immediately acquire an authority so concentrated that it threatens the ruler. Auxiliary forces present the opposite problem: their danger lies in their valor. A capable, united army under its own officers can accomplish the requested task so effectively that the prince loses the capacity to determine what follows.

Historical Examples

The example of Pope Julius II illustrates the pattern. After witnessing the poor performance of his mercenaries during the enterprise against Ferrara, he turned to auxiliary troops and arranged with Ferdinand of Spain to receive cavalry and infantry. The decision arose from a real military failure, but the remedy placed the pope in the arms of a stranger. The desire to secure Ferrara led him to exchange the visible weakness of hired troops for the less visible danger of foreign strength.

The outcome seemed to vindicate him only because an unexpected intervention prevented the full consequences. After the auxiliaries were defeated at Ravenna, the Swiss suddenly descended and drove the victors from the country. Pope Julius therefore escaped both possible forms of captivity: he did not remain a prisoner of his enemies, because they were put to flight, and he did not become a prisoner of the auxiliaries, because the victory was won by other forces. His good fortune rescued him from a policy that the argument nevertheless treats as rash.

The Florentine siege of Pisa supplies another warning. The Florentines possessed no soldiers of their own and brought ten thousand French men-at-arms to the operation. Instead of simply solving a military deficiency, the decision exposed Florence to greater peril than any previous crisis had done. The numerical strength of the foreign force did not compensate for the political vulnerability created by dependence upon it.

A still more destructive instance occurred when the Emperor of Constantinople summoned ten thousand Turkish soldiers into Greece to protect himself from neighboring enemies. Once the war ended, the troops refused to depart. Their continued presence transformed temporary assistance into permanent subjection and became the beginning of Greece’s servitude to the Infidel. The episode shows how an invitation made for immediate security can alter the political condition of an entire country: the foreign army does not need to betray its employer in the field; it can simply remain.

Auxiliaries and the Logic of Political Dependence

Auxiliary troops are described as more dangerous than mercenary arms because they bring ruin ready-made. Mercenaries may require time and favorable opportunities before they can harm the prince, even after winning a battle. Auxiliaries, by contrast, arrive already united, commanded, and capable of acting as a single political instrument. Their organization minimizes the prince’s supervision while maximizing the foreign commander’s capacity for independent action.

The argument therefore rejects the comforting distinction between military victory and political safety. A victory gained through foreign aid is not counted as a true victory, because the prince has not demonstrated mastery of the force on which his position rests. The battlefield result may be favorable while the constitutional result is disastrous. The ruler has won an engagement only by making another power indispensable, and indispensability is the beginning of subordination.

This principle belongs to a broader doctrine of foresight. A prudent ruler must address political disorders while they are still remote and inchoate, when remedies remain possible, rather than waiting until danger becomes obvious and incurable. The same reasoning applies to military alliances. Avoiding immediate war by inviting a stronger foreign force may postpone rather than remove danger. Time can bring evil as well as good, and delay may allow the invited power to acquire influence, territory, or allies that cannot later be displaced without a greater conflict.

The danger also resembles the general problem of relying on another power to create one’s own greatness. A ruler who strengthens an outside force for his immediate purposes may eventually become dependent on the very power he has helped to raise. The political cost is especially severe when the foreign force enters a divided province, where weaker parties may welcome it against a local ruler. A stranger who is invited by discontented inhabitants can gather support from those who resent the existing authority, while the prince who summoned him discovers that his supposed ally has acquired an independent base.

Cesare Borgia and the Turn to National Arms

Cesare Borgia’s career provides the clearest movement from auxiliary dependence toward military self-reliance. He entered Romagna with French auxiliary troops and used them to take Imola and Forli. The forces were effective enough to produce territorial gains, but their usefulness did not make them trustworthy. Their foreign origin meant that his success rested upon an instrument he did not fully own.

Cesare Borgia next tried mercenary forces, taking the Orsini and Vitelli into his pay because he believed they would pose less danger than the French. This change reduced one form of dependence but did not solve the underlying problem. The mercenaries proved fickle, false, and treacherous while under his command. Their contractual service gave them no durable reason to sacrifice themselves for his state, and their own interests could diverge from his at any moment.

He consequently dismissed them and fell back upon troops of his own raising. The change was measured not only in battlefield capacity but also in political reputation. His standing increased as he moved from dependence on the French, through reliance on the Orsini and Vitelli, to command of his own forces and resources. He was never regarded so highly as when everyone perceived him to be the sole master of his army. The sequence makes national arms the practical foundation of reputation: a prince appears powerful when his authority is visibly rooted in forces that answer to him rather than to an outside patron.

Hiero of Syracuse demonstrates the same conclusion in a more extreme form. After becoming captain of the Syracusans’ armies, he recognized that a mercenary force modeled on the Italian condottieri was unusable. Because he would neither retain nor disband the soldiers, he caused them all to be cut to pieces and thereafter made war with native troops alone, without outside aid. The episode presents the harshest possible rejection of military intermediaries: the ruler secures political control by eliminating the force whose independent interests make obedience uncertain.

Political Significance

The doctrine of auxiliary troops is ultimately a doctrine of command. A state is secure only when its ruler can determine where its forces go, why they fight, and what happens after victory. Foreign auxiliaries reverse that relationship. The prince appears to command them because he has requested their arrival, but the decisive authority remains with the potentate who supplied them and the officers who lead them.

The preference for national arms also links military organization to the durability of political order. A prince who depends on another ruler’s troops lacks a stable foundation in the same way that a newly elevated ruler who depends on another person’s favor lacks secure support. Sudden elevation through fortune may carry a man to power but leaves him struggling to establish foundations afterward; foreign military aid similarly carries a state through a crisis without giving it the means to defend itself independently. In both cases, borrowed support is easy to acquire and difficult to survive.

The concept therefore opposes the temptation to purchase immediate safety at the price of future autonomy. A ruler may prefer defeat with his own forces to victory with auxiliaries because the former preserves the possibility of learning, reform, and rebuilding, whereas the latter may leave him victorious only under another power’s protection. Auxiliary troops are not merely soldiers from elsewhere. They are the visible form of a political bargain in which the supposed beneficiary risks becoming the instrument of the benefactor.