While the consequences of Yevgeny Prigozhin’s challenge to Vladimir Putin’s power on 24 June remain to be seen, one lesson that Putin might choose to draw from history was learnt by other European nations many centuries ago. As a ruler, the idea of contracting someone else to fight on your behalf with a private army may seem very attractive, but it usually comes at the cost of that private army challenging – sooner or later – your monopoly on violence. No English king suffered more from the problem of contracting unreliable private armies, arguably, than Edward IV. On the face of it, Edward had the makings of a highly successful king; his competitor, Henry VI, lacked the capacity to lead in battle at all, and Edward’s father, Richard of York, had already done a lot of the military and political heavy lifting for the House of York before his death in battle at Wakefield in 1460. But in the turmoil of the Wars of the Roses there was little breathing space for the new king to consolidate and centralise his authority over the ‘overmighty subjects’ on whom the new regime relied for its very existence.

In a late medieval nation with no standing army, where armies were mustered locally according to need, it would be easy to say that kings were always forced to rely on private armies; and in the notorious case of the Marcher Lords, one group of the English aristocracy were given a level of military autonomy that always made them a threat – not to mention the autonomous and frequently rebellious old Anglo-Norman aristocracy of Ireland. There was a difference, however, between raising a non-professional royal army through the usual channels – relying on local magistrates and knights holding land from the crown in feudal service – and becoming dependent on a professional liveried militia, such as the forces of Richard Neville, 16th Earl of Warwick – the Prigozhin of fifteenth-century England. While forces raised by the crown were funded by Parliament or by the king (and therefore by taxation), private armies were funded by magnates themselves. Known to history as ‘the Kingmaker’, Warwick succeeded not only in putting Edward IV on the throne, but also in temporarily deposing him, at the Battle of Edgcote in 1469. Warwick also managed to marry two of his daughters to Edward IV’s brothers, the dukes of Gloucester and Clarence – the former eventually becoming king as Richard III.

The prevalence of private armies whose first loyalty was to their magnate – and not to any king – was a problem for both sides in the dynastic wars of the fifteenth century. Perhaps no case of a privately raised army changing sides in a battle is more notorious than that of Sir William Stanley, whose troops switched allegiance at the Battle of Bosworth and turned against Richard III. In the hours when Moscow was being threatened by the advance of Wagner Group mercenaries, some footage on social media showed Wagner symbols and advertising being torn down in the Russian capital. In the fifteenth century, likewise, the symbolism of private armies and militias was key to indicating their allegiance. Originally worn by a magnate’s servants like a sort of medieval bellboy’s uniform, in the violence and chaos of the fifteenth century ‘liveries’ – uniforms based on a magnate’s heraldic badge – were transformed into private military uniforms and notably excluded any reference to the authority of the crown, such as the cross of St George, which had designated English royal armies since at least the fourteenth century.

In 1468 Edward IV attempted to restrict the practice of magnates issuing armed followers with liveries (known as livery and maintenance), but since local courts were themselves subject to intimidation by liveried retainers and the statute still permitted liveries for ‘lawful service’, the statute was effectively unenforceable. Indeed, it was not until the reign of Henry VII (who always had a gift for creating new layers of bureaucracy) that a court came into being that was powerful enough to clamp down on magnates with liveried retainers. Even Henry Tudor did not ban the practice outright; a great noble’s right to a retinue of liveried men was, in and of itself, unassailable. But, under statutes enacted in 1487 and 1504, Henry required aristocrats to seek a licence to have liveried retainers; if they failed to do so, they risked being fined astronomical sums. Furthermore, Henry VII applied this policy evenly and without favour, unlike Edward IV, who exempted those closest to him from any attempted restrictions on private armies. Not only that, but Henry VII created a powerful new symbol of loyalty to the new regime, the Tudor Rose, a unifying and charismatic emblem that challenged the old livery badges.

Like Henry VII with his system of licences, Vladimir Putin seems to have been trying to bring the Wagner Group under the control of the Russian state; like Edward IV, however, his closeness to Prigozhin may have blinded him to the potential threat posed by the overmighty subject. Time and again in medieval history, however, challenges came not just from those who might be expected to oppose the king, but also from those closest to him – and it is perhaps a feature of the brittleness of autocracy that a challenge can come from anywhere. No-one can be safely relied upon, as Edward IV discovered of his own family; his brother George, Duke of Clarence rebelled and joined the Earl of Warwick.

Prigozhin’s private army is only a tiny fraction of the size of the huge armed forces of the Russian Federation, but it seems better trained, more motivated and more agile than the Russian army. Likewise, in the Middle Ages royal armies were ad hoc compositions of more or less trained men, while the wealthiest magnates could maintain combat-ready standing armies of retainers. It would seem that, for Vladimir Putin, the dangers of relying on such private armies need to be learned afresh.