Joseph Luzzi, a professor at Bard College in New York, is a Dante scholar whose books argue for the relevance of the great Italian art and literature of the late middle ages and Renaissance to our own times. A great populariser and advocate of the humanities in public life, he has done for Dante what his Bard colleague Daniel Mendelsohn did for Homer in An Odyssey and other books.

This short volume tells the story of the Hospital of the Innocents in Dante’s home town of Florence, a building Luzzi has been fascinated by since encountering it in 1987 on his college year abroad. The Innocenti, as it is known, was the first institution in Europe devoted solely to the care of unwanted children. The first foundling, named Agata because she was left by its gates on Saint Agata’s Day 1445, had been nibbled at by mice.

At the time, children made up half the population of Florence, and many were abandoned. The church demanded “be fruitful and multiply” and condemned the use of contraception, which was primitive anyway. Babies were left inside church doorways, dumped in rivers and chucked on to rubbish tips. They were, in the lively Tuscan vernacular, the gittatelli – the thrown-away ones. Many were the result of unwanted sexual advances, especially on servants by their masters. In a fiercely patriarchal society, the majority of children deposited at the Innocenti were girls. The mothers would break a coin in two and hang one half round the baby’s neck in the hope of meeting them again.

The Innocenti was built by the Silk Weavers Guild in an era when the contribution that wealthy Florentines were expected to make to civic life was measured in counting-house ledgers like “a business’s gains and losses”. The building had arches designed by Filippo Brunelleschi, architect of the Duomo, and it housed (and still houses) works by the greatest artists of the Renaissance: Ghirlandaio, Botticelli, Piero di Cosimo, Andrea and Luca della Robbia. By caring for and educating its children, the Innocenti saved many of them from poverty, sex work or trafficking. And it lessened some of the stigma of illegitimacy, which in Renaissance Italy meant to be “born without honor, a status equivalent to a living death”. To suggest, as the book does in its subtitle, that the Innocenti “discovered” our modern idea of childhood feels a stretch. But it did contribute to the now accepted notion that the fate of every child matters, and inspired similar institutions across the world, including Thomas Coram’s Foundling Hospital, established in London in 1739.

Luzzi mostly tells the story straight, without the blend of memoir and scholarship that characterises his previous books. He does make brief reference to where his interest in caregiving comes from: he became a father and widower on the same day, when his heavily pregnant wife was killed in a car crash, and his mother and sisters helped him raise his daughter. For more on that compelling story, I recommend his book In a Dark Wood.

But this book mostly paints a wonderfully sensual and cinematic picture of early modern Florence in all its grubby, gorgeous detail. The Innocenti, like the city itself, mixed high-minded motives with utilitarian and cruel ones. It farmed out babies to wet nurses, who would use them as cash cows, almost starving them and sometimes even collecting payments after they had died. And it spent its donations on expensive art while feeding its charges on bread and water, the bread made not with flour but with the bran they also fed to the mules. The boys were taught a well-rounded curriculum of maths, Ciceronian rhetoric and music; the girls learned to weave and were pushed into a life of domestic service, even when the hospital’s directors knew that this opened them up to sexual exploitation.

The Innocenti emerges as an absorbing case study in how the beautiful frescoes, arching columns and paintings of the Italian Renaissance masked “the sweat and suffering of forced labor, the raping of slaves, the abuse of children”. The words of the German critic Walter Benjamin might have been this book’s epigram: “There is no document of civilisation which is not at the same time a document of barbarism.”

Much of what we know, or think we know, about the court of Henry VIII comes directly from the paintings of Hans Holbein. There’s the famous portrait of the king himself – puffy, phallic and cruel, looking more like a murderer than a monarch. But there is also ascetic Thomas More, hiding his cruel streak behind fine bones, and sly yet thuggish Thomas Cromwell, with those shifty eyes and the beginnings of a double chin. “Hans the Painter” did the wives too – an appropriately sketchy drawing of Anne Boleyn, a saintly portrait of Jane Seymour who died after giving birth to Henry’s heir, and a pin-up version of Anne of Cleves.

It was this last portrait that caused an international incident in 1539 when Holbein was sent by Henry to the Low Countries to check whether Anne was pretty enough to be his next wife. Based on Holbein’s portrait, Henry committed to the marriage in absentia, only to be horrified when the actual Anne arrived on the Kentish coast, looking “nothing so fair as she hath been reported”. The union lasted six months.

In this magnificent book, the first scholarly biography of Holbein in more than 100 years, art historian Elizabeth Goldring characterises the Cleves affair as a “debacle” but also points out that it was a rare misstep for Holbein, whose portraits generally struck contemporaries as uncannily lifelike. And even though today we have no way of judging their verisimilitude, there is no mistaking their essential vitality: you would swear Holbein’s people are blinking and breathing before you, ready to reach out and shake your hand.

Consider his early pictures of the Dutch humanist Erasmus, commissioned in 1523 when both men were living in Basel. The middle-aged scholar’s deeply etched face manages to convey both generic qualities of intellectual rigour and benign humanism while remaining utterly individual, with a wide, curving mouth and deep-set eyes. And there is a certain cheeky humour in evidence, too. In the background of the portrait now hanging in the National Gallery is a Latin tag, presumably by Erasmus (Holbein had only a rudimentary education), which calls attention to the artist’s juvenile cockiness: “I am Johannes Holbein, whom it is easier to denigrate than to emulate.”

It was Erasmus who was responsible for getting Holbein to Britain in 1526, when he wrote a letter recommending the young man to his friend Thomas More. More, who was on his way to becoming lord chancellor, quickly commissioned a series of portraits. Holbein presciently rendered the saintly More as saturnine, with the beginnings of cruelty about his mouth. Here was a man who was simultaneously devoted to God while busily installing a set of stocks at his Chelsea home with which to torture heretics. The fact that More famously opposed Henry’s attempts to obtain a divorce and marry Anne Boleyn may explain why the portrait that now hangs in the Frick Collection in New York has two large, centuries-old vertical splits. Boleyn was reputedly so angry with her nemesis that she dragged Holbein’s painting – the next best thing to More himself – from the wall and flung it on the ground.

All that lay in the future, though. After the portraits, Holbein busied himself with painting the large More clan as the epitome of a happy Christian household. Well-dressed women dominate this canvas, with More’s clever daughters and female wards consulting their prayer books while Alice, his second wife, wears an ostentatious crucifix. This mood of prosperous devotion is in startling contrast to a picture Holbein did on his return to Basel the following year. Portrait of the Artist’s Family shows a red-eyed, bone-tired Elsbeth Holbein looking like a soiled Madonna with her two peaky children. Having been left behind to function as a single mother and workshop supervisor while her husband was getting famous in England, Frau Holbein can hardly be blamed for not bothering to disguise her exhaustion and resentment.

The chronology of Holbein’s life is complicated and opaque, but Goldring does a good job of keeping things on track without pretending to absolute certainty. It appears that Holbein didn’t stay in Basel very long once the city had become a religious war zone, with Protestant activists creating a bonfire out of Catholic vanities. Instead, he returned to the Henrician court, this time permanently, leaving Elsbeth to fend for herself. To add insult to injury, he seems to have taken up with a woman in London, fathering another two children.

Returning to England was, however, no guarantee of political safety. Thomas More would soon be executed for refusing to recognise Henry as the supreme head of the new Church of England, and it says a great deal for Holbein’s survival skills that he did not go down with his erstwhile patron. Instead, on this second and final trip, he shrewdly pivoted towards the new man Thomas Cromwell and the new queen, Anne Boleyn.

For Anne’s coronation in 1533 Holbein built an extraordinary triumphal arch out of papier-mache painted to look like marble. (Goldring reminds us that, like all Renaissance artists, “Maister Hans” could turn his hand to anything.). It would take another five years, though, before he finally got what he had been angling for – a place on the royal payroll and the title of “King’s Painter”. What sealed the deal was a series of huge murals undertaken for the Palace of Whitehall. It was here that Holbein’s iconic rendering of Henry first appeared, the one that is recognised around the world today.

Barrel-chested and bulked out with padded shoulders and an enormous codpiece, Holbein’s Henry stands glittering and thuggish, ready to take on all-comers. According to a slightly later source, to be in the presence of this Whitehall Henry was to feel annihilated, which was exactly the intended effect – since the real flesh-and-blood Henry was in a far more parlous state. A recent jousting accident had left him with ferocious headaches and a leg so putrid that you could smell him coming. It was hard not to feel pity.

All of which is ironic, given that there was no artist better than Holbein at confronting the brute realities of ailing flesh. Fifteen years earlier, he had painted The Body of the Dead Christ in the Tomb, a grotesque rendering of Jesus’s decomposing corpse. In this lifesize image, the mouth and eyes hang open, the skin is already going green and the fingers have begun to stiffen with rigor mortis. More than 400 years later, Fyodor Dostoevsky would find the painting so disturbing that his wife insisted on dragging him away, terrified that it would trigger an epileptic seizure. Nonetheless, Holbein’s visceral painting made its way – almost as a character in its own right – into The Idiot (1869).

In her introduction, Goldring seems wary of characterising her extraordinary book as a biography. This is doubtless because of a long-held scholarly suspicion of treating works of art as if they are mere anecdotes culled from an artist’s life, rather than autonomous creative objects. But in the case of Hans Holbein it is impossible to see how one could do otherwise than plunge into a world of rich and vital lived experience. His great achievement was to bring before us the living, breathing men and women who plotted, suffered, contrived and triumphed through the most terrifying decades of English history. And it is Goldring’s achievement to show us the process by which this magic happened.