he looks like, how he ages, and (perhaps) something of how his internal life prints itself on his features: Caravaggio, like Hitchcock, is present in so many of his pictures. He is to be found in the unsettlingly mocking Self-portrait as Bacchus, completed when he was about 22, and in a last, harrowing appearance in The Martyrdom of St Ursula, just before his death at 38, while he moves around the fringes of his altarpieces, torn and remorseful, implicated in the betrayal of Christ and in the failure to save his saints from torture and death.

He seems never quite to have fitted in where he wanted, and if a welcome mat were laid out for him he would contrarily foul it in a sudden fiery quarrel. Now he is beyond stoning people’s shutters, knocking offenders on the head or accidentally killing an enemy, and he cannot run from the final perfect marriage of biographer and subject. It may have taken time, but – like the inescapable hound –  Graham-Dixon has tracked Caravaggio through archives and inventories, painstakingly piecing together minute pieces of information, which are assembled like pixels so that you can stand back from the whole for a fleeting glimpse of the uncatchable fox.

The notes reveal the scope of the research behind this remarkable book, from articles on poverty, bare feet and plague in the Renaissance, via Montaigne, Pliny and St Bonaventure, to advice on Neapolitan dialect, as well as every book and essay ever written on Caravaggio. But even more than for the scholarship which underpins it, this book must be admired for the acute perception and empathy with which the paintings are unpicked.

The 1593-94 Boy with a Basket of Fruit, contemporary with the Bacchus, is not, in Graham-Dixon’s reading, either a demonstration of trompe l’oeil skill or the sensuous depiction of a catamite. It is a painting of the Groom in the Song of Solomon, and thus a type of Christ. The fruit he carries is the metaphorical fruit with which the Bride is compared: “an orchard of pom­egranates … thy breasts [like] clusters of grapes … the smell of thy nose like apples”, while he is the Beloved, “his locks are bushy, and black as a raven …”. He stands in celestial light, against the shadows of death, and the fading vine leaves reveal grapes from which the wine of the Eucharist will be pressed.

The naked adolescent St John the Baptist in the Capitoline Museum is a counter in Caravaggio’s “game of rivalry and homage” with his namesake, Michelangelo, a running game which weaves through the book. The Baptist’s strangely abandoned pose, causing the painting to be seen as a sexy pastoral, is taken from one of Michelangelo’s classicising nudes on the Sistine Chapel ceiling, whom Caravaggio has reinvented as a realistic teenager, bony and dirty, revelling in the light of divine prophecy and embracing the sacrificial Lamb of God.

This dedication to realism, to representing the miraculous as though taking place in the here-and-now, is another thread on which the paintings are hung. Graham-Dixon shows that Caravaggio’s approach to art is steeped in the teachings of Carlo Borromeo, learnt in the Milan of his youth: an “implicit rejection of high art [for] … traditional, popular visual representations aimed … at the promotion of mass piety”. Hence the peeling away of extraneous detail, so that, for example, The Death of the Virgin or The Resurrection of Lazarus  are shown in such a way as to involve the spectator intimately, in scenes apparently acted out by his next-door neighbours. Or, as Martin Scorsese explained the influence of Caravaggio on his own work, “Making films with street people was what it was really about …”