In 1362, a roving army of unemployed soldiers descended on southern France. They called themselves the Grandes Compagnies—the Great Companies. These weren't foreign invaders. They were the very men France had paid to fight the English, now turned loose with no war to occupy them. They pillaged, extorted, and terrorized the countryside for years. The French crown had created a monster it couldn't control.

This wasn't an aberration. It's the oldest pattern in military history. From ancient Rome to Renaissance Italy to modern Africa, the story repeats with eerie consistency: hire mercenaries when you need them, then watch helplessly as they become your next problem.

The fundamental flaw of mercenary service lies in its basic transaction. A soldier who fights for pay has made a contract, not a commitment. His loyalty extends exactly as far as the next payday—and not an inch further. This creates what military historians call the auction problem: any employer can be outbid.

Rome learned this repeatedly. The Praetorian Guard, originally an elite bodyguard unit, eventually realized they held more power than any emperor. In 193 CE, after murdering Emperor Pertinax, they literally auctioned off the throne to the highest bidder. Didius Julianus won by promising each guardsman 25,000 sesterces. He lasted sixty-six days before a real army showed up and the Praetorians conveniently switched sides again.

The economic logic is inescapable. Professional soldiers who sell their skills develop exactly that—professional detachment. They're not fighting for homeland, family, or cause. They're working. And workers go where the pay is best. Medieval Italian city-states discovered this when condottieri commanders would sometimes negotiate mid-battle, switching sides for better terms while their employers watched in horror.

Takeaway

Mercenary loyalty is a market transaction. The moment someone offers better terms, the contract is open for renegotiation—often at the worst possible moment for the original employer.

Successful mercenary commanders face an interesting career question: why keep working for someone else? They have battle-hardened troops, tactical expertise, and often more military power than their employers. The leap from employee to owner becomes almost logical.

The mamluk system offers the most dramatic example. Islamic rulers from Baghdad to Cairo purchased Turkish slave soldiers, trained them into elite warriors, and relied on them for military power. By 1250, the Mamluks had simply taken Egypt for themselves, ruling as sultans for the next three centuries. The hired guards became the dynasty.

This pattern repeated across cultures. Germanic mercenaries in Roman service gradually realized they didn't need Roman employers. The Varangian Guard in Constantinople accumulated such wealth and influence that Byzantine emperors grew afraid of them. In Renaissance Italy, Francesco Sforza rose from mercenary captain to Duke of Milan. His company had grown so powerful that taking the duchy was easier than continuing to serve it.

Takeaway

Military power without political legitimacy is unstable—but military power tends to acquire legitimacy over time. Give mercenaries enough success, and they'll eventually wonder why they're still taking orders.

Today's private military contractors exist in a legal gray zone that would look familiar to medieval employers. Companies like the former Blackwater (now Academi) or Russia's Wagner Group operate with significant autonomy, sometimes unclear accountability, and their own institutional interests that may diverge from their employers' goals.

Wagner's trajectory in Africa follows the historical script almost perfectly. Originally deployed as deniable military force for Russian interests, the group accumulated mining concessions, political influence, and local alliances. By 2023, Wagner forces had become kingmakers in several African nations—and their attempted mutiny in Russia showed how uncomfortable even their original employer had become with their power.

The fundamental tension hasn't changed in three thousand years. States need military capability but often lack internal resources. They hire external force. That external force develops its own interests. The relationship becomes complicated, then adversarial, then sometimes catastrophic. Modern corporations add legal complexity, but the underlying dynamics would be perfectly recognizable to any Roman emperor watching his Praetorians grow restless.

Takeaway

Technology and terminology change, but the mercenary problem remains structural. External military force always develops independent interests, and those interests eventually diverge from the employer's goals.

The mercenary problem isn't a bug in military history—it's a feature of how power works. Outsourced violence creates autonomous power centers. Those centers develop their own survival instincts. Eventually, the tool becomes a rival.

Every civilization that relied heavily on hired soldiers learned this lesson. Some adapted by integrating mercenaries into citizenship structures. Others collapsed when their hired protectors became conquerors. The pattern suggests something uncomfortable: there may be no clean solution, only various ways of managing an inherently unstable arrangement.