Ruled by the prince of darkness

LEOPOLD II of Belgium was one of the most evil men to have walked the planet. In many ways he was even more despicable than the most famous monsters of history, for they usually made no bones about the terrible things they did, and rationalised their actions (General Franco, with his "redemption through suffering" is a good example). By his greed, avarice and wickedness, Leopold was responsible for the deaths of 10 million people in the Congo in the 20 years from 1888, while sucking out in exploited surpluses the equivalent of pounds 1.76bn in today's money.

Yet he denied angrily that he had done anything wrong. As with Franco and many others in the class described by LBJ as "our sonsofbitches", the Anglo-Saxon rulers of the world let him get away with his crimes. So there is no happy ending to Adam Hochschild's story.

It was HM Stanley who did Leopold's initial work for him. Sent back to found a state along the banks of the mighty river he had charted in 1876- 77, Stanley delivered to Leopold in 1884 the skeleton of the future Belgian Congo. At the Berlin Conference of 1885, called to sort out the "scramble for Africa", the Great Powers did something so extraordinary that nobody has ever really been able to explain their thinking. They gave the new Congo territory to Leopold as his personal fief, unrestrained by any laws. With more justification than Louis XIV, Leopold could have said: "l'etat, c'est moi." He owned the Congo, lock, stock and barrel.

The detestable Leopold, a monarch who wanted to be a plutocrat, sucked super-profits out of the Congo, first in ivory and later in wild rubber. He achieved his staggering profits by enslaving the indigenous population, brutalising them and murdering all he could not cow.

The collection of rubber engendered specific problems, as the slave labourers had to penetrate deep into the jungle to tap the trees. Since he could not afford large numbers of whip-wielding thugs in the jungle, Leopold solved the problem by taking the tribesmen's women and children as hostages, threatening to kill them if the astronomical rubber quota for each village was not met.

In the case of the most recalcitrant tribesmen, Leopold simply exterminated them. Using "divide and rule" tactics, he sent in local levies from hostile tribes. These killers were offered a per capita bounty but, to prove their murders, they had to bring back a severed right arm for each "kill".

This nightmare - whose atmosphere is so well described in Conrad's Heart of Darkness - was first exposed by a young man working in Brussels for a British-owned shipping line, Leopold's maritime link between Belgium and the Congo.

The 26-year-old Edmund Morel noticed three things from his study of the company's manifests: vast quantities of arms were being sent out secretly to Africa; nothing was being exported to the Congo to pay for the imports of ivory and rubber (so how had they been acquired?); and someone was skimming off the top, since the amount of ivory repatriated to Belgium was far in excess of the amount indicated in official returns. Morel thus correctly deduced the existence of a slave state in central Africa.

Aged 28, Morel quit his job in Belgium to become the greatest British investigative journalist of the age. He soon laid bare Leopold's racket with unimpeachable evidence. There had been reports of atrocities in the Congo before, but these had been dismissed as contingent events. Morel showed the Congo atrocities were necessary, imbricated in the very fabric of Leopold's pirate state.

The Foreign Office sent Roger Casement out to the Congo to learn the truth, hoping that he would refute Morel, but he came back with detailed confirmation. Despite attempts by the FO to censor his reports, Casement worked secretly with Morel. In 1904 they founded the Congo Reform Movement.

The sequel is moderately well known. Despite serpentine twistings by Leopold, international pressure built up, especially when celebrities such as Sir Arthur Conan Doyle and Mark Twain joined the campaign. In 1908, a year before his death, Leopold was forced to hand over his fief to Belgium, at which point the ill-starred Belgian Congo was founded.

First, Leopold extracted his pound of flesh. He conned the Belgian government into buying the territory, even though he had already embezzled 32m francs in government loans. Belgium had to assume 110m francs' worth of debt, to agree to pay another 45m to complete Leopold's lunatic building programme, and to pay him 50m francs in instalments from future revenues in return for "all he had done for the Congo".

Hochschild has a riveting story to tell, and does it justice. He has used all the best sources, is painstaking and meticulous, and is aware of all the dark parallels in his tale. He quotes Primo Levi: "Monsters exist. But they are too few in number to be really dangerous. More dangerous are... the functionaries ready to believe and to act without asking questions." This is a cautionary tale for the ages.

Frank McLynn