Fox News host Bill O'Reilly presented a bold new idea this week. He called for the formation of a mercenary, "anti-terror" army that would combat Islamist militancy around the world. It would be "English-speaking," have U.S. training, and be able to rapidly parachute into all sorts conflict arenas where the enemy may lurk. As The Washington Post's Erik Wemple already noted, the idea is so absurd that it has been panned by guests on O'Reilly's own show.

But that didn't prevent it from getting genuine airtime elsewhere, including a segment on CBS that earnestly rendered O'Reilly's scheme into a graphic:

The Fox News anchor is apparently under the conviction that such a force could circumvent the "politics" that otherwise impede unilateral American action on the world stage. But it's hard to see how the creation of this sort of army would not, from the very first moment, be subsumed by messy politics. As it is, there are already hundreds of thousands of armed private contractors deployed in various troubled corners of the world, operating sometimes in a gray area of murky legality and morality. In the past century, the West's most famous mercenaries have rarely been paladins of the just.

Perhaps WorldViews is taking O'Reilly's TV stunt a bit too seriously. Ever since peoples and empires started fighting wars, soldiers of fortune have played some part. Here are three disastrous episodes from the very long history of mercenaries that could have some bearing on the strategic calculations in O'Reilly's universe.

The Carthaginian revolt

Mercenary armies and legions of foreign fighters were staples of all ancient empires. The Carthaginians, whose empire spanned from their capital in what's now Tunisia to the whole western rim of the Mediterranean, vied with Rome for supremacy over this stretch of the ancient world. Its armies comprised a diverse mix of soldiers, including mercenaries from what's now France, Spain, Italy, Greece and Libya. In 241 BC, following defeat to the Romans, Carthage found itself unable to adequately pay the tens of thousands of mercenaries in its employ. They revolted and seized the empire's second biggest city on the North African coast. "They detached the rest of Africa," chronicles the Roman-era historian Appian, "and brought over to their side some Numidians [an ancient North African people], and received into their ranks a vast number of fugitive slaves, and pillaged the Carthaginian possessions in every direction." It took Carthage four years to put down the mercenary rebellion, in a bloody conflict known as the Truceless War.

The Catalan Grand Company

One of Europe's first distinct mercenary armies, the Catalan Grand Company, was created by Roger de Flor, a Sicilian-born ex-Knight Templar, in 1281. After fighting campaigns in the Western Mediterranean, Roger took some 6,500 Spanish mercenaries to Constantinople and entered the employ of the Byzantine emperor in 1303. The Byzantines expected the company to take the fight to the Turks, who were encircling their domains. But the Catalan Grand Company almost immediately took to brawling the streets of Constantinople and later clashing with other units in the Byzantine army. Their reckless campaigning and pillaging through the Anatolian countryside eventually led to the Byzantines killing Roger in an ambush in 1305.

But the company lived on, attracted more fighters from lands near and far, and even began to carve out territory for itself, including chunks of what's now modern-day Greece. The History Channel has a terse account of how that came to pass:

They marched to Greece and found work as muscle for the Duke of Athens. But when a dispute arose over back pay, the Catalans once again went to war with a former employer. After crushing the Greek armies and killing the Duke at 1311’s Battle of Kephissos, they found themselves the de facto lords of the Duchy of Athens. Amazingly, the mercenaries managed to consolidate their power and rule over large swaths of Greece for more than 75 years until an army from Florence finally defeated them in battle. The remnants of the Catalan Grand Company disbanded shortly thereafter.

The White Company

Sir John Hawkwood, a British mercenary captain who cast a long shadow over 14th century Italian history, is one of the more fascinating, enigmatic characters of medieval Europe. He was also ruthless. The Italian peninsula then was not a country but a chessboard of kingdoms and wealthy city-states, many which enlisted foreign regiments to fight their battles. The White Company, which Hawkwood would eventually take command of, was one of the more feared units operating at the time. "They were all young men bred in the long wars of England and France, fierce, enthusiastic, quite used to the routine of killing and looting," recounts one contemporary Italian chronicler.

In 1377, on orders of their paymaster at the time, the Cardinal of Geneva, the company slaughtered up to 5,000 civilians in the city of Cesena. Hawkwood's charges at various moments would battle the Pope in Rome, Florence, Milan and others. Rather than wage open war, his company would pillage and raid, as they did for a whole month in 1364 outside Florence until they were paid a fortune by the city to simply leave.

Not a creature of ideological sentiment, Hawkwood rebuffed calls to go on a crusade against the Turks and, instead, continued to consolidate his holdings and power in Italy. Florence, after facing him as an enemy for so long, eventually enlisted him in its service on a significant retainer. When he died in 1394 of natural causes, the city gave him a state funeral. A fresco of Hawkwood (known as Giovanni Acuto in Italy) still can be found in the Duomo. It reads: "John Hawkwood, British knight, most prudent leader of his age, and most expert in the art of war."