Marc Chagall, a portrayer of dreams and a poet of color who was one of the most famous painters of the 20th century, died last night at his home in the French Riviera village of St. Paul de Vence.

A child of the 19th century, who gave artistic form to the concepts of the unconscious and the irrational that have played so great a role in the culture of this century, Chagall was 97.

The cause of his death was not immediately known. His wife said he collapsed about 8 p.m. and died.

Born in a small town on the Polish-Russian border, Chagall had lived and worked in pre- and post-Revolutionary Russia, in Germany and in France, and -- after fleeing the Nazis -- for several years in the United States.

His works -- luminous, glowing with color, hallucinatory in their evocative power -- can be found all over the world, and include easel paintings and murals, etchings, sculpture and brilliant stained-glass windows.

From a public drawn by their warmth, charm and, frequently, joyousness, they earned for him vast popularity.

Critics and scholars were often -- although not always -- admirers as well. To many of them, Chagall was, perhaps more than any of his famous colleagues, the man who captured in paint and on canvas the insubstantial stuff that dreams are made of.

Over the years Chagall contributed to and was associated with such prominent and significant artistic movements as Fauvism and Cubism, to name just two. Some also saw in his work an affinity to German Expressionism.

But over a long and productive life, he kept changing; as recently as eight years ago, he persisted in his refusal to classify himself as belonging to any single school of painting.

One of 10 children of a religious Jewish family, Chagall was reminded vividly of his religious background at several important junctures in his life.

Much of his art has Jewish and religious themes. He illustrated the Bible, and visited Israel several times, and on one occasion created 12 large stained-glass windows for an important synagogue there at the Hadassah Hospital.

A national museum was built in Nice for him and his monumental cycle of paintings titled "The Biblical Message."

Chagall, a prophet and practitioner of modernism, was born July 7, 1887, near the Russian town of Vitebsk and into a culture that was in many ways a survival of the medieval.

He was reared in a wooden house set among other simple houses, in a neighborhood full of the arrivals and departures of tradesmen and relatives and the wanderings of an assortment of domestic animals.

These images, both idyllic and mysterious, along with such memories as peering through the dormer windows of his house at the town of Vitebsk just across the river Dvina, remained with him through his life.

Despite the Biblical commandment against the creation of graven images, Chagall turned, as a child, almost by accident, to drawing.

One day he watched a schoolmate copy an illustration. He was stunned. The schoolmate laughed at his naive amazement.

That incident, Chagall recalled later, "roused a hyena in me." He began to draw, first copying from magazines, then improvising. In time came formal training, first with a provincial painter, later in St. Petersburg. For a time he took lessons from Leon Bakst.

In 1908, he produced "The Dead Man," significant because it was his first recognized masterpiece. Inspired by an early encounter with death, it was transmuted into a work of expressionist art.

In 1910, a patron rescued him from what might have been a career confined to folk art. He was sent to Paris.

Paris was art: elation, ecstasy, euphoria -- and the enhancement of the incipient drive toward an almost hallucinatory mode of expression.

From the cubists, he learned some discipline that chastened his wilder flights of fancy. But his style remained his own.

Cubism, he said, was "too remote from the heart."

In his early Paris years, his colors grew lighter; objects became more buoyant. Seemingly unrestrained by gravity or convention, they began to drift and float and soar.

"My art . . . " he said, "is perhaps a wild art, a blazing quicksilver, a blue soul flashing on my canvases."

In his paintings of the 1910-1914 period, scholars later saw the first stirrings of surrealism. But at the time, Paris was not buying Chagall's pictures.

A one-man show of 200 canvases in Berlin in 1914, however, won praise from the expressionists there and opened his way to fame.

World War I found him back in Russia, where he married his childhood sweetheart, Bella Rosenfeld, his first wife.

Then there was a move to Petrograd, and a job in the bureaucracy. After the Russian Revolution, he served briefly as commissar of fine arts for the Vitebsk district.

In time, he became entangled in the toils of the politicization of art and in 1922, repelled by Socialist Realism, he left Russia. He went first to Berlin, and then to Paris.

He set about creating a series of 107 etchings to illustrate Gogol's Dead Souls. In addition, he immersed himself in the French landscape. From this period came what might be described as visual fables of French life.

But the years from 1931 on were uneasy, with the rise of Nazism becoming increasingly more menacing. Scholars detected in Chagall a new sense of his Jewish origins, and a new seriousness.

His painting "The Revolution," completed in the late 1930s, was a gigantic commentary on the Spanish Civil War.

Danger was heightening in France for Chagall, and on June 23, 1941, the painter and his wife, art works in their luggage, arrived in New York.

A stranger to English, isolated from his old life, Chagall devoted himself to his work, first in New York City and later in Connecticut.

Images of grief and sorrow abound in the paintings of these years, even those which still showed the influences of legend and fantasy.

Bella died on Sept. 2, 1944. Known as his most discerning critic, she was also seen as the principal source of the happiness that infused his work.

It was at least six months before he could resume painting.

One of his pictures demonstrated his characteristic style. It showed Bella as a bride entering another world.

After the war he returned to France, settling in Vence in 1950.

Although there were visits, on commissions, to Israel and the United States, most of the rest of his working life was spent near Vence.

He began to branch out into new techniques, including ceramics and lithography, as well as creation of mosaics and murals.

Stained glass windows in French churches came as a kind of prelude to his work on the synagogue in Jerusalem.

During this work, he said, "I felt as if father and mother were looking over my shoulder, and behind them were Jews, millions of other departed Jews of yesterday and thousands of years ago."

The "light of heaven is in these windows," he said, "and by this means they are part of the good God."

Chagall remarried in 1952, to Valentine (Vava) Brodsky, who survives.