In August 1576, when Titian died -- of plague -- in his shimmering, beloved, pestilential Venice, the Register of the Dead there gave his age as 103.

That proud exaggeration (most scholars now believe he was a few years shy of 90) was of Titian's own devising. He frequently pretended to be older than he was. Old age increased his wealth. He used his long gray beard, his accumulated cunning -- and his status as a monument -- to wring a few more ducats from his many regal patrons. "With an insistence painful to the sensitive," wrote scholar Erwin Panofsky, "the aged Titian collected money from all sides." And old age gave him freedom. None of history's great masters -- neither Rembrandt, nor Picasso, nor Goya with his last black works, nor Matisse with his cutouts -- has played a grander endgame. Titian died a kind of prophet. The free, unpolished brush strokes of his last amazing style, his ultima maniera, prefigure those of Rubens, Velazquez and Manet.

"Titian: Prince of Painters," the rich sampling of his pictures that goes on view today at the National Gallery of Art, is shaped like a crescendo. Grand at the beginning, it's vastly grander at the end.

It closes with a painting of pure, redemptive horror. "The Flaying of Marsyas," once again in Washington, must be among the strongest, strangest paintings of all time.

That summarizing masterpiece -- with its knife-cut flesh, its lapdog lapping gore and its boilings of pure paint -- tears the viewer's heart. No straight-edged laws of order, no rules we can discern, govern this great picture. All here is liquidity, and churnings of emotion. The blood-dimmed air is seething. The actors in this drama aren't formed of solid, polished stuff set in crystal space, but of palpitating light. Titian, from the start, had peered beyond mere surfaces. Here, in his last painting, he tears away the skin of things. The world itself seems flayed.

There is about his art a remarkable fluidity. Venice is a water world, a place of glints and shifting movement, and the greatest works of art of this greatest of Venetians have a kind of ceaseless flow. The eye that tries to trace his brush strokes and his finger strokes (he often painted with his fingers), or the heart that tries to follow the complex feelings he evokes, is seldom allowed rest.

Titian's colors move. He sometimes paints in shadowed tints (look, for instance, at the browns and grays of the "Man With a Glove," borrowed from the Louvre), but then a sudden brilliance flares, as if the dark clouds had just parted -- a sky shines sun-bright yellow, a floating angel's gown flames with crimson. One feels that flowing, too, in the complicated, deeply human stories his pictures tell. Titian's peerless portraits -- of emperors and children, Venuses and martyrs -- speak of pieties and open lusts, pomposities and terrors. They have a truth-telling conviction, a psychological acuity and a grandeur that is near-Shakespearean.

Other painters of the Renaissance idealized their sitters. Titian conjures thinking, breathing people. No wonder popes and doges, warriors, kings and princes, hired him incessantly. The story of the Holy Roman Emperor, Charles V, bending down to pick up a brush the painter dropped, may well be apocryphal, but still it has the ring of truth. Titian's letters to grandees (they're mostly about money) are unctuous and obsequious, his brush is deferential, but he never merely flatters. When we look into his portraits -- of cunning old Pope Paul III huddled in his velvet cape, or fierce Francesco Maria della Rovere in his coal-black suit of armor, or the pope's 11-year-old nephew, both vulnerable and armed -- we know the sitter's soul.

It's something in the glance, perhaps, or the message of the pose. It's as if Titian's finest paintings have within them hidden mirrors that let us see, reflected, our own passions and anxieties, weaknesses and prides. No earlier European had better understood the coiled sinuosities of severe male power. His rulers look like rulers. And how he teased their lusts. His famous blonde and sexy nudes have a kind of heated glow. His plump and naked "Venus With an Organist and a Dog," brought here from the Prado, has skin that seems to light the crimson velvet of her bed. The great "Danae" from Naples -- Zeus, who here appears as a shower of golden coins, is making love to that sweet nymph -- is equally desirable. (The famously suggestive "Venus of Urbino," marveled Giovanni della Casa in 1544, "is a Theatine nun next to this one.") Titian's soft-skinned nymphs present more than their bodies. They make eroticism manifest. His severed heads and rotting flesh do the same with gruesomeness. His Virgins are pure piety. His pictures never bore.

Occasionally they terrify. The "Marsyas" from Czechoslovakia, newly cleaned for this exhibit, overwhelms the viewer. In this mighty picture, wrote scholar Sydney J. Freedberg, "all things coexist, subsumed into one resonating harmony, the comic and the cruel, the terrible and the sublime, ugliness and magisterial beauty... . {The painting} works a kind of alchemy, transmuting horror into art."

That eerie double knowledge -- you're looking at a brush stroke, you're looking at a breathing man -- is there from the beginning. Titian's figures are less idealized, less polished, than those of sweet-souled Raphael. They're less muscular by far than mighty Michelangelo's writhing male demigods. Leonardo's perfect, otherworldly saints are neo-Platonic philosophies transmuted into flesh. Titian gives us living beings.

For the best part of a century, he ruled the art of Venice, and not of Venice only. The great nobles of his era -- the kings of France and Spain, two Holy Roman Emperors, the Medicis, the d'Estes and the princes of the church -- though they warred on one another in other realms of life, clamored for his pictures. In terms of fame and wealth and the greatness of his patrons, to say nothing of longevity, Titian was the most successful painter of his times.

And what times they were. Shakespeare, Martin Luther, Suleiman the Magnificent, Durer, Raphael, Michelangelo, Leonardo, and Christopher Columbus too, were alive when he was. It is tempting to look backward at the 16th century as a kind of golden age of Mediterranean grandeur. But those were times of horror too.

Rome was sacked while Titian lived. The bleeding severed heads of hundreds of Venetians were stacked in stinking piles by the armies of the Turks. Poisoning was commonplace, as were betrayals and intrigues. Warfare was near-constant. And then there was the plague. Through all this turmoil Titian kept on working, and pleading for more money, and painting for the rich.

But not only for the rich. Many wondrous artists give their all to public life. Shakespeare, for example, retired while still young, and never wrote another word as far as we can tell. But Titian's last and strangest pictures feel as if they were painted not for patrons. He made them for himself.

Consider, for example, his two very different versions of "Tarquin and Lucretia." Both show scenes of rape and, by implication, murder. The larger and more finished work comes from the Fitzwilliam Museum. Dated 1571, it was painted for King Philip II of Spain, one of Titian's greatest patrons. It is, despite its scene of rage, a thing of courtly splendor. The vest worn by the murderer is shot with threads of gold; his victim's bed is covered with velvet and fine linens, and although she is nude, her fair skin is set off by gold and ruby bracelets and a necklace of rich pearls. The killer's rage is clear -- from the position of his knee, from the fury in his eyes, and from the clashing of the colors of his deep red trousers and his orange socks. The colors of the smaller work (this one comes from Vienna) are comparatively subdued, and Lucretia wears no jewels. Here, instead, the violence seethes in Titian's paint. The wild strokes resemble abstract expressionist stabbings. This hoarse scream of a picture is a personal, not public, work. It's like an old man's nightmare -- of innocence defiled, anger uncontrollable, and harsh, remembered lust.

That note of stinging horror is heard often in this show. One senses it particularly in the three ceiling panels the master painted for Santo Spirito in Isola (the gallery, correctly, has displayed them high above the viewer's head). Panofsky called their scenes -- of Cain and Abel, the Sacrifice of Isaac and the David and Goliath -- "a trilogy of homicides." Bright red blood is dripping from Abel's smashed-in head. David gazes upward in a hymn of thanksgiving. One supposes that he's just vanquished vast Goliath -- until one sees the greenish, stench-suggesting pallor of the giant's severed head. It looks as if it's been rotting there for weeks.

When Titian made the "Marsyas," so Freedberg has argued, the painter was responding to a news story just as horrible. Word had reached Venice of the fate of Marcantonio Bragadin, a Venetian commander of a fort on Cyprus taken by the Turks. Bragadin, when captured, had been tortured without mercy: His nose and ears had been cut off; then his bleeding body, with sacks of stones upon it, was dragged around the city's walls; he was then tied to a column and skinned alive. That the Turks were soon defeated, wholly unexpectedly, at the Battle of Lepanto, must have made his awful death seem a sort of presage of miraculous release. That Titian could turn scenes of suffering and hate into paintings of great beauty says much about the passionate, redemptive power of his art.

Titian, in old age, must have thought much about time. One of the oddest pictures here, his "Allegory of Prudence" from the National Gallery, London, displays three human faces above those of three animals: a wolf, a lion and a dog. As Panofsky has explained, the wolf stands for the past that devours, the lion for the present that acts and the dog for the future that flatters with its promises of hope. The three faces in the picture speak of hope as well: Titian's aged self-portrait peers into the past. Gazing toward the future is his heir presumptive, his young nephew, Marco, "whom he particularly loved." Staring full face at the viewer is the painter's son, Orazio, to whom Titian seems to say, the present time is yours.

Titian's hopes for continuity and for his family's rich future were not to be fulfilled. The plague of 1576 claimed some 50,000 of the 175,000 inhabitants of Venice. It killed the venerable master and, a few days later, Orazio as well. Their splendid house in Venice, filled with pictures and rare objects, was looted days after their deaths.

The present exhibition includes some 50 paintings, a number of them newly cleaned, and three painted ceilings, one of which contains 19 separate panels. The gallery's display is a somewhat smaller version of the Venice exhibition, which was held this summer in celebration of the (presumed) 500th anniversary of Titian's birth.

The Uffizi Gallery, Florence, the Prado of Madrid, the National Gallery, London, the Louvre of Paris, and many other institutions have provided loans. Many masterworks are missing: London's "Noli me tangere," the Borghese Gallery's "Sacred and Profane Love," the Gardner Museum's "Rape of Europa," and the Louvre's "Entombment," to name but a few. Still, a Titian show as large and sumptuous as this one will not soon be seen again. Two Italian companies, Galileo Industrie Ottiche and Silvio Berlusconi Communications, helped to pay its bills. The accompanying catalogue -- much of it translated, badly, from the Italian, requires heavy slogging.

"Titian: Prince of Painters" will remain on view in the Gallery's West Building through Jan. 27.