People in Denbigh had been consulted and most were in favour. The councillors were promptly jumped on from a great height by academics and authors claiming that Stanley had been connected with genocide in the Congo. Other critics questioned why a Welsh town council thought an explorer who had pretended to be an American deserved a statue. Bloggers blogged, tweeters tweeted, letters and articles appeared, many attacking the statue, and the councillors must have wondered what had hit them. But seven months later, they have faced down their critics and will unveil their man today.

Why do they care so much about him in Denbigh? In 1847, aged six, the person who would one day call himself H M Stanley was dumped, weeping, outside the workhouse. He had been abandoned by his parents at birth, and now by his prosperous uncles. After 10 years in the workhouse, he emigrated to America. At 29, against all the odds, he achieved world fame by “finding” Dr Livingstone in Africa.

The moment he returned to Wales his family hounded him for cash, which he gave them. But though he wanted to be thought an American to conceal his “shameful” illegitimacy, they sold stories about his origins to the press. Yet he never lost touch with them, and in his fifties renewed his links with Denbigh by adopting an infant great-nephew, living in poverty in the town.

To become an unrivalled African explorer from such beginnings is a kind of miracle. In a single majestic 7,000-mile journey, Stanley circumnavigated Lakes Victoria and Tanganyika, establishing where the Nile rose, and then became the first human to navigate the Congo for 1,800 miles from the heart of Africa to the Atlantic. His three white companions perished, as did half of his 227 African porters, from malaria, smallpox, drowning, starvation and attacks on their party.

Last August, 50 signatories to an anti-statue letter, published in The Daily Telegraph, implied that if councillors were to “honour the imperialist Stanley”, they would convict themselves of being racists and colonialists (real insults to Welsh people). The proper place for Stanley, critics declared, was in an exhibit like the International Slavery Museum in Liverpool, where he could sit beside King Leopold II of Belgium, demonstrating his involvement in that monarch’s crimes against humanity. “It is impossible,” declared the academics, “to disconnect Stanley, or any other imperialist of the period, from the suffering [caused by land-stealing and exploitation by Europeans].” As Stanley’s only biographer to have had access to his private archive in Brussels, I find their certainty baffling. Although Stanley worked as Leopold’s agent on the Congo from 1879 to 1884, it is entirely possible to “disconnect” him from land theft in the Congo and from the subsequent suffering.

Stanley did not steal land from Congolese chiefs through his treaties but rented sites on which to build trading stations. When Leopold demanded that the chiefs “delegate to us their sovereign rights … and grant us everything”, Stanley resisted. The Congolese “are not subjects”, he replied, “but it is we who are simply tenants … these chiefs own the soil”. Leopold appointed other officers to invent the treaties he wanted. Stanley’s originals were then “lost” and forgeries substituted.

One genuine Stanley treaty eluded the king. Signed near present-day Kinshasa in 1881, it demanded no sovereignty, pledged payment of rental to chiefs, and did not bar non-Belgian traders. I discovered this treaty in Brussels and it is a model of fairness.

Stanley was sacked as the king’s agent a decade before Leopold’s “Red Rubber” atrocities started. On learning about the mutilations and murders, Stanley wrote to The Times condemning such crimes and begged Leopold to admit an international commission of inquiry. The king never spoke to him again. Stanley wrote before leaving the Congo: “If Europeans will only study human nature in the vicinity of Kinshasa, they will go home thoughtful men, and may return again to this land to put to good use the wisdom they should have gained.”

Opponents of the statue also claimed that because Stanley shot Africans, he stood self-condemned. Yet from the 1870s, with the Arab slave trade breeding hatred for strangers, almost all European explorers in Africa were obliged to take lives on occasion. Near Lake Victoria in 1875, Stanley was attacked and lost 22 men in two days’ fighting. “We went into the heart of Africa self-invited, therein lies our fault,” he wrote, “but it was not so grave that our lives when threatened should be forfeited.”

Baker, Brazza, Cameron, Gordon all killed Africans in self-defence but kept quiet. Even Dr Livingstone (who has many statues) shot African slave traders to prevent them from capturing converts at a mission. “These things may be done, but not advertised,” General Gordon advised.

Stanley did not listen. As a journalist in America covering the government’s war against the Comanche, his editors had urged him to exaggerate the killings and fighting. Foolishly, he did the same in his African newspaper reports. Stanley was no racist. He hated slavery and was, he said, “prepared to admit any black man, possessing any good qualities, to my friendship, even to brotherhood”. On the Congo he described Dualla, a Somali, as his prime minister and paid him the same as white officers. When a black was called “nigger” by a white, he objected to “that ugly derisive word”.

The colonisation of Africa is often characterised today by its worst disasters: Leopold’s rape of the Congo and the Germans’ massacre of the Herero people of south-west Africa. Thus Stanley’s colonial sympathies strike some people as disgraceful. Yet “saintly” Dr Livingstone had viewed colonies as a humanitarian necessity. By the 1870s, Arab Swahili slave traders were causing misery throughout central Africa. By the mid-1880s over half a million people were being displaced or killed annually.

During the 19th century, two million slaves were dragged by Swahili traders across the Sahara to Egypt or shipped from East Africa to Arabia and the Gulf. African rulers were also involved; Livingstone declared the Arab slave trade “a small evil by comparison with the perpetual capturing and sale of children [by Africans]”. Such facts are downplayed today because political correctness decrees that Africans suffered more at the hands of Europeans than Arab or native conquerors.

Of course, when Europeans divided up Africa in the 1880s and 1890s, they did not do so only to save victims of the slave trade and an expanding gun frontier. Economic motives loomed large. But the Victorian humanitarian impulse was not a sham. What would have happened if the Arab slavers had been allowed to rampage through Africa unchecked? Recent events in Darfur give an inkling of the continent-wide disaster that would have occurred without European intervention. There could be no escape into an unspoiled past. Arabs had arrived in the seventh century, Portuguese in the 15th, and neither was going to ease the transition into the modern world which Africans would have no choice but to make.

African resistance to British intruders was widespread, though (with the notable exception of Sudan) mainly confined to small, scattered actions over several decades. Yet in a mere quarter century, colonial administrations all but ended the indigenous and Arab slave trades, ushering in a brief era (at least in British and French colonies) of peace, security and incorrupt government.

Africans were disconnected from their culture, but, as John Iliffe has written, to see colonialism as merely “destroying tradition is to underestimate African resilience [and also] to underestimate how much industrial civilisation offered 20th-century Africans”. Colonies brought an unprecedented transfer of human skills and scientific knowledge. European medicine and sanitation immensely increased life spans and population size. So it is ironic that 50 years after the end of empire, colonialism is often blamed by guilt-filled Europeans for more of Africa’s late 20th-century woes than are superpower sponsorship of dictators, corrupt Big Men, ethnic war, Aids, malaria, drought and an unfair international trade system.

If the statue spat can make us think in a more even-handed way about our imperial past, it will have been valuable. How will we build a genuinely inclusive society in Britain, if our confidence in the political ideals we have inherited (and which colonised people rightly invoked to gain their freedom) is constantly undermined by post-imperial guilt? At a time when one Harvard academic has grotesquely compared the British Empire to Stalin’s Russia, where 51 million people died, I say three cheers for the councillors of Denbigh for putting their most remarkable son on a plinth, and for not running for cover at the first whiff of high-minded grapeshot.

Tim Jeal is the author of ‘Stanley: the Impossible Life of Africa’s Greatest Explorer’ (Faber). His new book ‘The Nile Explorers: The Triumph and the Tragedy of a Great Victorian Adventure’ will be published by Faber in September.