Between "The

By ROBERT HUGHES

Giulio Romano was so well known in his time that he is the only painter mentioned in any of Shakespeare's plays. Famous, and rather vulgar. If Raphael was the epitome of grace among artists of the High Renaissance and Michelangelo the paragon of sublimity, then Giulio was all licentious facility. So ran the judgment of our Victorian forebears, who could not quite forgive Raphael's best pupil for his indelicacy. An air of brilliant second- rateness still clings to his name. Those who can thrust their way through the crowds in Palazzo Te in Mantua and manage a long look at the enormous Giulio Romano show that has been the city's main event this fall (it closes on Nov. 12) will have the best chance any public has had since the artist died in 1546 to judge him for themselves.

& Although Giulio Pippi de'Giannuzzi was born in Rome, took the city's name, worked in Raphael's studio and, as a very young man, must have known both Michelangelo and Leonardo da Vinci, it was in Mantua that he found his voice as an artist. As architect and painter to Federico II Gonzaga, he became Mantua's virtual artistic dictator in his 20s and remained so until he died at the early age of 47. There, projects poured from him in an undiverted stream: not only frescoes and panel paintings and the innumerable sketches that preceded them, but also designs for palaces and villas and town houses (including his own house in Via Poma), for heraldic emblems, tapestries, urns, salvers, jewelry and every other class of luxury object a Renaissance patron might feel the itch to have. Indeed, Giulio's first job in Mantua was a tomb for the Duke's favorite dog, a long-legged bitch that had expired while giving birth to a litter of puppies.

The instrument of this colossal output was drawing. Giulio was incontestably a great draftsman. Drawing was as natural to him as speech; Raphael, in fact, took him on as a studio assistant when Giulio was not much more than ten. The grace, the spontaneity of his pen line -- rushing over the paper as though impelled by the lightest inflection of thought, quick but always controlled, strengthened by brown washes that confirm its structure -- does not always translate to the paintings and frescoes, where it seems heavier and overdetermined. But with Giulio, design and invention were inseparable, and their combination is worn so lightly that one may not realize how difficult were the problems he set for himself. How do you create long processional friezes of figures based on a Roman triumph, as in the Stucco Room at Palazzo Te, without monotonously repeating poses and gestures? How do you cram an imagined temple with such an excessive throng of spectators that the Circumcision of Christ looks more like a PEN dinner thrown by Gayfryd Steinberg, and yet keep the action coherent? Virtuosity was in Giulio's nature.

The big change in his fortunes came in 1524, when he was 25. Giulio was approached by the Venetian writer and rake Pietro Aretino, who wanted illustrations for his Sonetti Lussuriosi (Salacious Sonnets). Giulio produced 16 drawings, each depicting a handsome couple rutting with the energy of blacksmiths in a forge, and sometimes in ways that would give you, me or Jesse Helms a hernia. These, like so much of Giulio's other work, may have come from a classical prototype: the spintriae, or tokens, stamped with obscene designs that were used for entry to Roman brothels in the second century A.D. The engraver Marcantonio Raimondi turned Giulio's I Modi (Ways, for short) into prints, and in this form they became enormously popular. They are still the most famous examples of visual pornography in Western art, although four centuries of attrition by prudery have destroyed almost all of them.

This outburst of randiness may have cost Giulio his Roman career. Raphael was dead, and his former assistants were now maneuvering on their own for the big commissions. But with Luther raging against Vatican corruption and a reformist chill blowing through the papal court, Pope Clement VII was not going to make a pornographer his official painter. At this point Baldassare Castiglione, Raphael's friend and author of The Courtier, fixed Giulio up with his job in Mantua.

There he had no rivals and no clergy breathing censoriously down the back of his neck. Federico II Gonzaga's court was a secular one; not even his tamest eulogists could have called the Duke pious. He was, however, brave, generous, greedy, obsessed with his own virtu (which meant prowess, not virtue) and determined to go down in history for his martial skills, his classical learning and his devotion to all vertical and horizontal forms of the chase. In Giulio, this son of Isabella d'Este found a court artist whose libidinousness and intelligence fit his own. Both men moved naturally in the imaginative world of a recovered antiquity -- the world of Apuleius and Ovid's Metamorphoses, the brutal sharp humor of Martial's epigrams, the fantasies of a Golden Age and the pseudo-scientific world view of astrology.

The great expression of their relationship was Palazzo Te itself, which Giulio designed from the ground up as a pleasure pavilion for Federico. This rectangular, single-story building, with its courtyards, pools, screen colonnade and enfilade of frescoed rooms, was Giulio's masterpiece. Its architecture would inspire many future designers, among them Inigo Jones and Sir John Vanbrugh. But its frescoes, which have been thoroughly and sympathetically cleaned in recent years, would be no less influential.

Some were almost impenetrably learned: no ordinary visitor today knows enough about Renaissance astrology to "read" the arcane designs in the Room of the Winds. Others are quite straightforward, like those in the chamber in which Federico had Giulio and his assistants paint life-size effigies of his favorite horses, with their names written underneath them. In between there is an amazing variety of images, some of which seem to teeter between grandeur and farce in a way unheard of in Renaissance art before.

In the Room of Psyche, the physical effervescence and the characters of the picnicking gods are set forth as explicitly as in a Roman pantomime, and one can easily see why Giulio had such an influence on Rubens and Poussin. Lusting, half-tipsy, bare bottomed and prone to fits of hilarity and rage, Giulio's Olympians cavort and cuckold one another across the walls to the accompaniment of all manner of phallic puns. When sword-brandishing Mars is seen pursuing Adonis, whom he has just caught in flagrante with his wife Venus, even the antique statues in the background display their truncated arms as a sign of impending castration.

But of course the most popular thing in Palazzo Te, now as then, is the Room of the Giants, where Giulio (whose taste for apocalyptic catastrophe may have been sparked by talking to Leonardo in Rome) painted Ovid's story of the gods' revenge on the rebellious earth giants. These bearded, stumbling palookas in their peasants' breeches, crushed by the fall of rocks and masonry, are done with literally colossal gusto. The whole windowless chamber seems ready, for a moment, to totter and fall on your head. No room in Italy gives you a clearer sense of the mannerist delight in bizarre illusion. If one could imagine a halfway point between Michelangelo's Sistine Chapel frescoes and the gee-whiz delights of Walt Disney, this would be it.