he title of the show is simple and stark: Slavery. Due to open this spring at the mighty Rijksmuseum in Amsterdam, this bold exhibition documents the importance of this abhorrent trade in the rise and wealth of the Netherlands, by juxtaposing shackles and slave inventories with works of art. There is a metal ring that has been in the Rijksmuseum since the 19th century. Previously catalogued as a dog collar, it is now thought to have been used on a human. There are other similarly chilling exhibits in this disturbing show – and at the heart of them all hang two renowned paintings by Rembrandt. Their inclusion is shocking. After all, there is no artist more overflowing with compassion and empathy than Rembrandt. Yet this exhibition at the Rijksmuseum, home to so many of his masterpieces, reveals a side of the painter’s career that sits badly with our view of him as an artist with an expansive vision of what it means to be human. In 1634, when he was a 28-year-old art star reeling in commissions by the herring barrel from the Amsterdam elite, Rembrandt van Rijn, the miller’s son from Leiden with a taste for the finer things in life, portrayed a young couple called Marten Soolmans and Oopjen Coppit. The works – they were given a portrait each – are usually seen as yet another example of the genius of Rembrandt, this most all-seeing of artists whose insight raises portraiture to an existential level. His paintings of married people are often informal moments of shared fun. But to portray this wealthy pair, he posed them apart for separate full-length canvases that have much in common with the show-off portraits Anthony van Dyck was doing in England. Both wear the sombre black of a Protestant republic, but this nod to morality is undermined by adornments signifying their bountiful wealth. Soolmans has glittering, crinkly silk stockings and enormous silvery flounces on his shoes, while Coppit flaunts pearls at her throat and gold on her wrists. Forget their pasty faces, Rembrandt seems to be saying, get a load of the bling. But there’s a deeply troubling side to this couple’s wealth – and Rembrandt may have wanted us to register that there was something amiss. Soolmans was heir to one of Amsterdam’s biggest sugar refineries, and the production of sugar at its origin point depended on slaves. From the 15th century up to the 1800s, Europe’s sweet tooth was fed by the captivity, transportation and brutal exploitation of Africans on sugar plantations in the Americas and Caribbean. The “golden age” of the Dutch Republic – when Amsterdam was the world’s busiest entrepôt and Dutch merchant ships traversed the world – saw the Netherlands muscling in on Iberian dominance in both sugar and slavery. The Rijksmuseum is stuffed with the artistic riches of the 17th-century Netherlands. For it to draw attention to the links between art, wealth and inhumanity in that age is a bold move. But it is time “to come clean”, Valika Smeulders, the museum’s head of history, told me – in order to “connect the collection to that history”. Parallel to the show, the Rijksmuseum has added labels to 80 objects in its collections that have links to slavery. This goes way beyond culture war cliches, though. In fact, Smeulders doesn’t see it that way at all. Far from a denunciation of the past, she argues, revealing this side of Dutch art can only make it richer. It certainly provides a new perspective on Rembrandt. The museum’s revelations about its twin portraits of this 1630s mercantile couple are certainly unsettling. Their focus is on Coppit: to what extent was this young woman aware of the cruelty and misery propping up the family business? “Did Oopjen know?” asks Smeulders. The Soolmans sugar factory was called ’t Vagevuur, The Fires of Purgatory (a rival was called Hell). This was a jokey reference to the heat of the refining process – but a real hell was created overseas, on the Dutch-owned plantations in Brazil, where slaves not only grew but also boiled cane sugar in huge vats, while being housed in squalor and subject to arbitrary discipline. Coppit never saw a slave plantation but her connections with slavery grew. After her husband died young, she herself became co-owner of The Fires of Purgatory. She then took as her second husband one Maerten Daey, a soldier who had not only spent time in the Dutch colonies but was prosecuted for raping an African woman there. She gave birth to his child. So what if the greatest artist of the golden age did portray these people whose fortune depended on slavery? Portraiture was profitable and Rembrandt needed the money. In 1634, the year he painted this couple, he married Saskia van Uylenburgh, and they had wealthy tastes. Perhaps it means nothing that his clients included not just the filthy rich but also the morally besmirched. A century later, when dominance of the slave trade had passed to Britain, Thomas Gainsborough would paint faces and frills whether his subjects were musicians or slaveowners. But this is Rembrandt. He is credited with a moral insight that goes beyond the conventions of his day. He portrayed Jewish people with sensitivity in an age of antisemitism. He crossed borders in his imagination, drawing impassioned copies of the Mughal miniatures that reached Amsterdam. Surely he didn’t just happily take the sugar money and give the couple what they wanted? That seems too simplistic a reading. Rembrandt appears almost to have intuited that a good deal of the Netherlands elite’s money, which bankrolled the proliferation of Dutch art in the 17th century, was tainted, perhaps even that it came directly or indirectly from Atlantic slavery. Certainly, the painter never got on with high society Amsterdam. Their portrait commissions didn’t satisfy him and the results, reflecting his determination to look beyond appearances, never pleased them. I last saw the portraits at the Rijksmuseum two years ago. I knew nothing about the pair except that it was clear Rembrandt couldn’t find anything to love about them. He is more interested in their buckles than their personalities. In Rembrandt’s hands, this becomes not flattery, not professional hackery – but a judgment. This couple got the chance to be observed by the artist with the most penetrating eye in history, and all they could muster was lace, silk, pearls and gold. Rembrandt shows us exactly what they are: rich non-entities using the veneer of wealth to conceal their vacuity, or something much worse. Things were very different later, in 1661, when he portrayed two African men. By then, Rembrandt was living a much more marginal existence. He still painted portraits but rarely took commissions, instead creating studies of suffering and experience, including his own face. Van Uylenburgh was dead and he lived with Hendrickje Stoffels. He went bankrupt and had to sell his fine house with its collections of costumes, armour and natural wonders. An inventory of his auctioned goods mentions a Portrait of Two African Men, which some historians claim refers to the Rembrandt now housed in the Mauritshuis in The Hague. Its raw style was typical of the last phase of his life. In that same year, 1661, Rembrandt was also working on a rare public commission that could have made him the darling of the Dutch elite again. He was asked to paint a patriotic history for Amsterdam town hall. But instead of a hearty scene of triumph, he painted The Conspiracy of Claudius Civilis, a desperate, Lear-like scene, drawn from an account of the Batavian rebellion in Tacitus’s Histories. Showing rebels agreeing to what looks like a futile suicide pact in an eerie pale light, the work was hated for its bleak view of Dutch history. It is not hard to imagine that those same disabused eyes, that looked so unsparingly at the past, were also directed at the present, and the most shameful secret of Rembrandt’s time: Europe’s exploitation of Africa. There’s a direct, surprising connection between The Conspiracy of Claudius Civilis and Rembrandt’s decision to make a radical portrait of two Africans. He got the commission after the first person the town hall asked, Govert Flinck, died. Flinck had been a pupil of Rembrandt but, after his master became odd and unpopular, he supplied an acceptable version of the Rembrandtesque. Flinck’s A Young Archer, in London’s Wallace Collection, is a painting of an African that has plenty of Rembrandt-like sympathy but is also imaginary and fanciful. It may not even be a portrait. There’s certainly little hint of anything untoward, certainly not slavery’s violence. Rembrandt’s portrait of two Africans in Dutch society is much less dreamy. The two men who posed for him were probably free or freed, part of a black community in baroque Amsterdam that historians are starting to rediscover. In fact, this community centred on the same neighbourhood where many Jewish people lived and Rembrandt had his house. So they may be his neighbours. Anyway, he portrays them intimately. Unlike the sugar-rich couple he chose to picture apart, these men are close together in an image of friendship and support. One rests his chin on the other’s arm. They seem to be sticking near to each other for human warmth in a hostile world. Rembrandt captures their anxiety and loneliness in a city that is no home. They seem sad – but you sense that it isn’t just a sadness for themselves. One wears a historical costume, armour redolent of ancient empires, as if he is a fallen king. There’s an overpowering air of loss, as if these are two men trying to find their place in a broken world. Rembrandt never went to Brazil, or Elmina Castle in present-day Ghana, or any of the other sites of Dutch enslavement. But that did not stop him sensing the stain of slavery on Europe and its ramifications. He could see it in these men’s eyes and captured it in this magnificent work. It’s a painting that shows his profound humanism, his alienation from his society’s rulers, and his fellow feeling for the wretched of the earth. It would make a superb companion piece to the portraits in the Slavery exhibition.