Who exactly was Caravaggio's dark-feathered god of love? What secrets this masterwork reveals about the rebellious artist

A youthful lad screams as his skull is forcefully held, a large thumb pressing into his face as his parent's powerful palm grasps him by the throat. This scene from The Sacrifice of Isaac visits the Uffizi Gallery, evoking unease through Caravaggio's chilling portrayal of the suffering child from the biblical narrative. The painting seems as if Abraham, commanded by God to sacrifice his offspring, could snap his spinal column with a solitary twist. However the father's preferred method involves the silvery grey knife he holds in his remaining palm, prepared to slit Isaac's neck. A definite element remains – whoever modeled as Isaac for this breathtaking piece displayed remarkable acting ability. Within exists not only dread, shock and pleading in his darkened eyes but additionally deep grief that a protector could abandon him so utterly.

The artist took a familiar scriptural tale and transformed it so vibrant and raw that its horrors seemed to happen directly in front of the viewer

Standing before the painting, observers recognize this as a real countenance, an accurate record of a young model, because the identical boy – identifiable by his disheveled hair and almost black pupils – features in several additional works by Caravaggio. In each instance, that richly expressive face dominates the composition. In Youth With a Ram, he gazes mischievously from the shadows while holding a ram. In Victorious Cupid, he smirks with a hardness acquired on Rome's streets, his black feathery wings demonic, a naked child creating chaos in a well-to-do dwelling.

Amor Vincit Omnia, currently displayed at a London museum, constitutes one of the most embarrassing artworks ever created. Viewers feel completely disoriented gazing at it. Cupid, whose darts inspire people with often agonizing longing, is shown as a extremely tangible, vividly illuminated nude form, standing over overturned items that comprise musical devices, a music manuscript, metal armor and an builder's T-square. This pile of items echoes, intentionally, the geometric and construction gear strewn across the floor in the German master's print Melancholy – save here, the gloomy disorder is created by this smirking deity and the mayhem he can unleash.

"Love looks not with the eyes, but with the mind, / And thus is winged Cupid painted sightless," wrote Shakespeare, just prior to this painting was produced around 1601. But the painter's Cupid is not blind. He stares directly at you. That countenance – sardonic and rosy-cheeked, looking with bold assurance as he poses naked – is the identical one that screams in fear in The Sacrifice of Isaac.

When the Italian master painted his three portrayals of the same distinctive-appearing kid in the Eternal City at the dawn of the 17th century, he was the most celebrated religious artist in a metropolis ignited by religious renewal. The Sacrifice of Isaac demonstrates why he was commissioned to adorn churches: he could take a biblical story that had been depicted numerous times previously and make it so new, so unfiltered and physical that the terror seemed to be occurring immediately before you.

However there existed a different aspect to the artist, apparent as soon as he arrived in Rome in the cold season that ended 1592, as a artist in his initial twenties with no teacher or supporter in the urban center, only talent and audacity. The majority of the works with which he caught the sacred metropolis's eye were anything but holy. What may be the very earliest hangs in London's art museum. A youth parts his crimson mouth in a scream of pain: while stretching out his dirty digits for a fruit, he has instead been bitten. Youth Bitten by a Reptile is eroticism amid poverty: viewers can discern the painter's gloomy room mirrored in the cloudy waters of the glass container.

The boy sports a rose-colored blossom in his hair – a emblem of the sex trade in Renaissance painting. Northern Italian painters such as Titian and Palma Vecchio portrayed prostitutes grasping blooms and, in a painting destroyed in the second world war but known through photographs, Caravaggio portrayed a famous woman courtesan, clutching a posy to her bosom. The message of all these botanical signifiers is clear: sex for sale.

How are we to interpret of the artist's erotic depictions of youths – and of one adolescent in specific? It is a inquiry that has split his commentators since he achieved widespread recognition in the twentieth century. The complex historical truth is that the painter was not the homosexual icon that, for example, Derek Jarman put on screen in his twentieth-century film Caravaggio, nor so entirely devout that, as certain art historians unbelievably assert, his Boy With a Basket of Fruit is actually a portrait of Jesus.

His initial works do make explicit erotic suggestions, or even offers. It's as if Caravaggio, then a penniless young creator, identified with the city's prostitutes, selling himself to survive. In the Uffizi, with this idea in mind, viewers might turn to an additional initial creation, the sixteenth-century masterwork the god of wine, in which the god of alcohol stares coolly at the spectator as he starts to undo the dark ribbon of his garment.

A few annums following the wine deity, what could have driven the artist to paint Victorious Cupid for the artistic patron Vincenzo Giustiniani, when he was finally becoming nearly established with prestigious ecclesiastical projects? This unholy pagan deity revives the erotic provocations of his early paintings but in a more intense, uneasy manner. Half a century later, its secret seemed obvious: it was a representation of Caravaggio's lover. A English visitor saw Victorious Cupid in about 1649 and was informed its figure has "the body & face of [Caravaggio's|his] own boy or assistant that slept with him". The name of this boy was Francesco.

The painter had been deceased for about 40 annums when this account was documented.