Who exactly was Caravaggio's black-winged deity of love? The insights this masterwork reveals about the rogue genius

The young lad cries out while his skull is forcefully held, a large digit pressing into his face as his father's mighty hand grasps him by the throat. This scene from The Sacrifice of Isaac visits the Uffizi Gallery, creating distress through Caravaggio's chilling portrayal of the tormented child from the scriptural account. The painting appears as if Abraham, commanded by God to sacrifice his offspring, could break his neck with a solitary twist. Yet Abraham's chosen approach involves the metallic grey knife he holds in his remaining hand, prepared to slit the boy's throat. A definite aspect remains – whoever modeled as the sacrifice for this astonishing work displayed extraordinary acting skill. Within exists not only fear, shock and pleading in his shadowed eyes but additionally deep sorrow that a guardian could betray him so utterly.

The artist took a familiar biblical story and transformed it so vibrant and raw that its horrors seemed to happen directly in front of you

Viewing in front of the artwork, observers identify this as a actual countenance, an accurate depiction of a adolescent subject, because the identical youth – identifiable by his tousled hair and nearly black eyes – features in two other works by the master. In every case, that highly emotional visage dominates the composition. In Youth With a Ram, he gazes playfully from the shadows while embracing a lamb. In Amor Vincit Omnia, he smirks with a toughness learned on Rome's streets, his black feathery appendages demonic, a naked child creating chaos in a affluent dwelling.

Victorious Cupid, currently exhibited at a British museum, represents one of the most discomfiting masterpieces ever created. Observers feel totally disoriented looking at it. The god of love, whose arrows fill people with often agonizing longing, is shown as a extremely tangible, vividly illuminated nude form, straddling overturned items that include stringed devices, a music score, metal armour and an architect's T-square. This pile of possessions echoes, intentionally, the mathematical and architectural gear strewn across the ground in Albrecht Dürer's engraving Melencolia I – except here, the melancholic mess is created by this smirking Cupid and the mayhem he can release.

"Affection sees not with the vision, but with the soul, / And therefore is winged Love depicted sightless," wrote the Bard, just before this work was produced around the early 1600s. But Caravaggio's god is not blind. He stares directly at the observer. That face – sardonic and rosy-faced, staring with brazen assurance as he struts unclothed – is the identical one that shrieks in terror in The Sacrifice of Isaac.

As the Italian master painted his three images of the same distinctive-looking kid in the Eternal City at the dawn of the 17th century, he was the most acclaimed sacred painter in a city enflamed by religious renewal. Abraham's Offering reveals why he was commissioned to adorn sanctuaries: he could adopt a scriptural narrative that had been depicted numerous times previously and render it so new, so unfiltered and visceral that the terror seemed to be happening directly before you.

However there was a different side to Caravaggio, evident as soon as he came in the capital in the cold season that concluded 1592, as a painter in his initial twenties with no mentor or supporter in the urban center, only talent and boldness. Most of the paintings with which he caught the holy metropolis's eye were everything but holy. What may be the very first hangs in the UK's art museum. A young man opens his crimson lips in a yell of pain: while stretching out his dirty digits for a cherry, he has rather been attacked. Boy Bitten By a Lizard is sensuality amid poverty: observers can discern Caravaggio's dismal room reflected in the cloudy liquid of the transparent vase.

The boy sports a pink flower in his hair – a emblem of the sex trade in early modern art. Venetian painters such as Tiziano and Jacopo Palma depicted prostitutes grasping blooms and, in a painting destroyed in the WWII but documented through images, Caravaggio portrayed a famous female prostitute, clutching a bouquet to her chest. The meaning of all these botanical signifiers is obvious: intimacy for purchase.

What are we to make of the artist's erotic portrayals of boys – and of one boy in particular? It is a inquiry that has divided his interpreters since he achieved mega-fame in the twentieth century. The complicated past truth is that the painter was not the homosexual icon that, for instance, the filmmaker put on screen in his 1986 film Caravaggio, nor so entirely pious that, as certain art historians unbelievably assert, his Youth Holding Fruit is in fact a portrait of Jesus.

His initial paintings do make overt sexual implications, or even propositions. It's as if the painter, then a destitute youthful artist, identified with the city's sex workers, selling himself to live. In the Uffizi, with this idea in mind, viewers might turn to an additional early work, the 1596 masterwork Bacchus, in which the deity of wine gazes coolly at you as he starts to untie the black ribbon of his robe.

A several years after the wine deity, what could have driven the artist to create Victorious Cupid for the artistic collector the nobleman, when he was at last becoming almost respectable with important ecclesiastical commissions? This profane non-Christian deity resurrects the erotic provocations of his initial paintings but in a increasingly powerful, uneasy manner. Fifty years later, its secret seemed obvious: it was a portrait of the painter's companion. A English traveller saw the painting in about the mid-seventeenth century and was told its subject has "the body & face of [Caravaggio's|his] owne boy or assistant that slept with him". The name of this boy was Francesco.

The artist had been deceased for about 40 annums when this account was recorded.