Historians have already drawn parallels between contemporary horrors and the horrors of the 14th century, when Europe was undermined by successive disasters, from the black death to the Anglo-French wars, to the peasants' revolts, to the schisms and corruptions of the Church.
Twenty-five years ago Barbara Tuchman published her brilliant narrative of the 14th century, A Distant Mirror, which began by explaining: "If our last decade or two of collapsing assumptions has been a period of unusual discomfort, it is reassuring to know that the human species has lived through worse before."
That "unusual discomfort" in 1978, with its limited wars and its settled frontiers of the cold war, might now appear relatively comfortable, and some would argue that in 2004 we are coming much closer to medieval slaughters and bloodthirty crusades. And one feature of the 14th century now has disturbing parallels with the contemporary world - the growth of mercenary armies which operate beyond the control of governments or nations.
Frances Stonor Saunders, who made her name with an exposure of the CIA's secret funding of intellectuals during the cold war, has now turned back seven centuries to look at these mercenaries, or "free companies", which were among the richest and most powerful organisations in the middle ages, as they offered their brutal services to kings and city-states across the continent, and plundered whole territories to finance their troops.
She has focused on one Englishman, Sir John Hawkwood who was the most notorious of the mercenary leaders across Europe, particularly in Italy. He was said to have an inspired the saying: "The Englishman Italianate is the Devil Incarnate"; but in Florence, which he sporadically defended against the invasions of Milan, he became an honoured saviour, commemorated by a huge fresco of Hawkwood riding in triumph on horseback, painted long after his death by Paolo Uccello.
That imposing memorial, as Saunders says, sums up the paradox of Hawkwood's career: he was knighted by King Edward III and retired to England as an Essex landowner; yet he was one of the most ruthless and destructive leaders of his time, whose ultimate loyalty was only to money. And the devastation which he caused was compared to that of the black death which preceded him.
Yet Hawkwood's murderous career - as recounted by the author with narrative skill, despite the inevitable lack of detailed documents - has its own gruesome logic and consistency: and it makes the chaotic tapestry of Europe in the late middle ages appear more unified and comprehensible than the lives of popes, kings or feudal magnates.
For while the territorial rulers were constantly struggling to make new alliances and to find money and taxes for their survival or aggrandisement, confined to their own regions, Hawkwood and his soldiers were free to move between England, France or Italy, regarding all Europe as their playground and source of profit, without any limitations of religious beliefs or local patriotism.
Many amateur students find the unity of medieval Europe hard to comprehend: as royal families emerge in different parts of the continent, the territories of France and England keep changing, and poets and writers such as Chaucer, Boccacio or Petrarch suddenly pop up as diplomats and negotiators in distant places. The rival popes in Avignon and Rome appear one moment as the spiritual rulers, the next as desperate predators and tax-collectors, selling redemption to maintain their extravagant courts. But through the eyes of Hawkwood and his rivals, the medieval chaos takes on some pattern. They saw popes and princes as their temporary paymasters who failed to grasp the realities of the power of the sword: they saw princes as potentials for ransoms, their fortresses as gold mines for lucrative sieges, and the surrounding lands as opportunities for pillaging and politics. They could deliberately starve peasants, to force them to change sides: as Pope Gregory XI ordered one of Hawkwood's marshals: "... to hinder the enemy from reaping the coming harvests, seeing that a deadly blow can now be inflicted: for if the enemy were to lose their harvests they would themselves be driven to act to the honour and profit of the pope."
What is most striking about Hawkwood is his rapid mobility through Europe, at a time when he depended on foot-soldiers and sailing boats; he never stayed in one place for more than two months: as soon as he saw the chance for profit, he moved across the continent as if it was his back-yard.
He was as mobile socially as geographically. In 1377, when he was 57, he married Donnina, then about 17, the daughter of Bernabo Visconti, the ruthless ruler of Milan. Soon afterwards he broke with Visconti, and in 1381 he was appointed ambassador of the British king, Richard II, to the Roman court, to reconfirm the alliance with the Holy See. After further adventures, working for the Florentines, he planned to return to England and arranged to endow a chapel and a convent in Essex, but at 72, he was too ill to travel from Florence where he died in 1394, mourned and honoured by the Florentines.
With all his respectability, no one could have illusions about Hawkwood's ruthlessness and cruelty. His most notorious act was the destruction of Cesena near Rimini in 1377, where English and Breton mercenaries murdered between 3,000 and 8,000 citizens in a cold-blooded reprisal over three days and nights.
Hawkwood's mercenaries were acting in the name of Pope Gregory, and later historians have put most of the blame on the pope, particularly since Hawkwood allowed a thousand women to escape to Rimini, "not be entirely infamous". But Saunders convincingly shows that Hawkwood master-minded the massacre with ruthless efficiency, and the survivors of the massacre were determined to revenge the atrocity, hunting down Hawkwood's troops until they had killed three hundred. The papacy itself had become fatally dependent on mercenaries: according to one source, the equivalent of 60% of the income of the Holy See in the 14th century was spent on professional soldiers. The tail was wagging the dog.
Medieval popes and princes could never altogether trust the mercenary leaders whom they paid, who could quickly turn against them for a better prospect. The fragile governments often longed to be rid of the "free companies" - which was one incentive for launching a further crusade, to provide a diversion for the plunderers and murderers.
The mercenaries thrived on the whole chaotic breakdown of order in the wake of plague, famine and war - which Saunders vividly describes. Sometimes inevitably her story suffers from the shortage of documents and authentic evidence, and leads her to speculate with phrases like "must have been". We long to know more about Hawkwood as a private man, and his own relationships with his family and his patrons. But she provides fascinating glimpses of Hawkwood's personality; including two brief letters written by him in 1393 arranging for his return to England, which emerged 70 years ago and are now housed in the British Library, the oldest extant letters in English.
Looking back on the greed and violence of that dreadful century it is hard to resist the temptation to make parallels with our own; particularly with the private armies which have emerged from the chaos of Africa, and have now spread to Iraq and parts of the Middle East and the old Russian empire. Weak governments and failed states will always provide a vacuum which can be quickly filled by military entrepreneurs, who can be discreetly encouraged by foreign governments strapped for cash.
The inability of monarchs to control the "free companies" seven centuries ago provides a warning to the Pentagon or the Ministry of Defence to stop using PMFs (private military firms) to do jobs that their own soldiers cannot do. The privatising of warfare can distort the diplomatic objectives of peace-making and stable governance, as the greed of mercenaries distorted the objectives of the medieval crusades.
The story of Hawkwood, which this book so vividly recounts, has it own timeless lesson: that the unleashing of greed into warfare, without government constraints, will lead to escalating violence that will prevail against any serious plans for peace.
Â· Anthony Sampson's book Who Runs This Place? is published by John Murray