The full-frontal menace of Caravaggio's boldest painting creates one of art's most unsettling encounters. Cupid is a real youth, modelled, it was said in the 17th century, after his own boyfriend "that lay with him". He poses as the god of love, wearing fake wings, grinning insouciantly at the embarrassed onlooker as the painting's severe light leads all eyes to his nudity. Is this what it felt like to be a cardinal eyeing up the trade in baroque Rome? Caravaggio's anarchistic tribute to the destructive power of desire – the stuff of civilisation lies defeated at Cupid's feet – is eternally worrying.Canova – Napoleon (1802-6)Napoleon Bonaparte was ruler of Europe when the brilliant neoclassical sculptor Canova portrayed him on a heroic scale, and totally naked, as the war god Mars. He is posed in the deity's lesser role – "bringer of peace" – a transparent piece of propaganda that adds to this statue's unique blend of genius and absurdity. Napoleon was apparently embarrassed by it, but the British thought it was great. This statue of a national enemy was presented after Napoleon's downfall to his vanquisher, the Duke of Wellington, and can be seen to this day in the Iron Duke's art collection at London's Apsley House.Wolfgang Tillmans – Kneeling Nude (1997)For Wolfgang Tillmans, everything is worth photographing and anything can be art – but art is just a way of seeing life. This man's nudity is not heightened to sublime aesthetic splendour, not photographed in black and white or ruthlessly posed. Nor is the sexual nature of the image in any way disguised or ennobled. Here is the raw beauty of life portrayed with naked desire.Michelangelo – Christ (1519-20)Michelangelo's Christ the Redeemer statueMuscled marble … Michelangelo's Christ the Redeemer, in Rome. Photograph: AlamyOnly Michelangelo had the power and courage to put a nude statue of Christ in a church at the heart of Rome. The muscled marble flesh of his all too human son of god flashes with life and pathos. It stands in Santa Maria Sopra Minerva, an ancient temple that became a Christian church, and combines the heritage of an ancient world that revered male nudity with Michelangelo's personal faith. His daring portrayal of Christ as a real, vulnerable, fully enfleshed man has yet to find full acceptance from the church – the ridiculous gilded covering of Christ's genitals was added long after his death, and still blemishes this sacred nude.Lucian Freud – Naked Man, Back View (1991-92)Lucian Freud and the performance artist Leigh Bowery created a modern masterpiece when Freud painted a series of nude portraits. Bowery's awe-inspiring physical presence and unpretentious dignity gave Freud's voyeurism and harsh honesty a worthy subject – someone who wanted to be remembered as colossal. Here is a nude of tragic grandeur, exhibiting his massive back as a modern answer to Michelangelo's furrowed studies of male flesh.Donatello – David (c 1440-60)No modern image is more blatantly sexual than Donatello's 15th-century statue of a naked youth, his smooth flesh set off by tight boots as he rests a foot in the soft hair of the slain Goliath. Androgynous and overtly teasing, it makes you self-conscious to look too long at this magnetic work in the Bargello Museum, in Florence. In fact, this is the first free-standing nude statue of the Renaissance. It embodies, literally, the revival of ancient Greece and Rome. Yet for all its centrality to the textbook history of art, Donatello's provocation refuses to become a bore. It throbs with ecstasy and danger.Belvedere Torso – Greek (1st century BC)This relic of a Greek statue was an overnight sensation when it was dug up in Rome in the early 16th century. Its most passionate fan was Michelangelo, who found a mirror image of his own intense charcoal drawings of male backs. It helped him see the pathos of the broken, in which he exults in his deliberately unfinished statues of Prisoners. It is still echoed in the male nudes of Mapplethorpe and Freud. The Belvedere Torso reveals that ancient Greek artists portrayed not only the perfect heroic body, but also the body suffering, tragic, heaving with pathos.Riace Bronzes – Greek (5th century BC)The nude is not a depiction of reality, the great Kenneth Clark told us – it is an idea. The idea of the nude as a symbol of heightened human glory comes from ancient Greece, where it evolved in archaic times. It achieved a poised "classical" beauty that has been imitated ever since. But very few of the original nude masterpieces of classical Greece have survived. They were made of fragile bronze and most are known today only through later marble copies, often deadly dull to the modern eye. That is why the Riace nudes, recovered from the sea off southern Italy in the 1970s, are so important. These immaculately preserved Greek statues from the fifth century BC reveal the true sensual majesty of the classical nude.Glykon (after Lysippos) – Farnese Hercules (3rd century AD)Farnese Hercules sculpture in ItalyWell sculpted … Glykon (after Lysippos) – Farnese Hercules Roman sculpture, in Italy. Photograph: AlamyThis mammoth of a man once loomed over idling Romans at the Baths of Caracalla in Rome. The ruins where it was discovered are among the mightiest in Rome: Caracalla gave bathers a sublime experience of architectural excess, in which this slightly monstrous nude must have fitted perfectly. It has haunted art ever since it was rediscovered in the Renaissance: proof that nudity can go beyond beauty into a realm of mysterious human extremity.Robert Mapplethorpe – Charles Bowman, NYC (1980)This ruthlessly beautiful photograph poses and crops its subject to emulate the Belvedere Torso and its close relations, Michelangelo's Prisoners . Before he discovered photography, Mapplethorpe wanted to be a sculptor. His biographer Patti Smith calls him "the boy who loved Michelangelo". You can see that here.(theguardian.com)ANN.Az