You could argue that the 18th century is the most overlooked epoch in the history of Western art. The National Gallery looks set to remedy that neglect this season. A pair of exhibitions will treat both the sentimental and rational sides of that lost century, will show art from both its English and French superpowers, and will cover high points in both painting and sculpture.

"Thomas Gainsborough, 1727-1788" gets things started next Sunday. Organized by the National Gallery in collaboration with Tate Britain in London, it is the first U.S. survey of the British painter's art. More than 100 works will cover the broad range of his prolific output. There will, of course, be a fine selection of his famous portraits, which manage to make the leaders of one of the world's first industrial and colonial powers look like sensitive poets contemplating nature. (Some of his female sitters can look as though they're part of his pastoral landscape's fauna: Gainsborough had a curious habit of making his female sitters look rather like sheep.) There will also be examples of his landscape pictures, central to the whole British tradition of painting rural scenery, as well as a sampling of his images of romantically impoverished country people.

On May 4, the National Gallery moves on to hardheaded, rationalist sculpture out of France, with "Jean-Antoine Houdon (1741-1828): Sculptor of the Enlightenment." Incredibly, this will be the first major exhibition ever devoted to Houdon, one of art history's greatest makers of sculpted portrait busts. He managed to leave us an unvarnished, strikingly convincing picture of his era's international elite -- including iconic images of George Washington and Benjamin Franklin. Such famous portraits will be supplemented by a sampling of less well-known works by Houdon in other genres, including sculptures illustrating historical and mythological subjects.

On Feb. 27, the Smithsonian's Hirshhorn Museum launches its new season with a touring show that has garnered raves elsewhere. "Gerhard Richter: Forty Years of Painting," organized by the Museum of Modern Art in New York, presents a wealth of work by one of the most influential, complex figures in contemporary art. From early pop-ish pictures of the 1960s, to politically informed work in photo-realism, to experiments in conceptual art, to massive abstractions made of colored oils squeegeed across the canvas, Richter has done everything he could to question all the things that paint can do while proving that the ancient medium still has things to say.

After all this European art, the Phillips Collection gives D.C. an important dose of things American. On June 7 it launches a major survey of pioneering U.S. modernist Marsden Hartley, the first such show in more than 20 years. The exhibition, touring from the Wadsworth Atheneum in Hartford, Conn., will include about 100 works, covering Hartley's long career and many styles. His first great series, painted in Berlin just at the outbreak of World War I, will be on display. These colorful, radically modern canvases looked wonderful when some were shown last year at the National Gallery; it will be great to see a bigger spread of them. The Phillips exhibition will also include landscapes from Mexico, France and Bavaria, as well as Hartley's famous late works, inspired by the artist's stays in Maine and Nova Scotia in the later 1930s.

"Gerhard Richter: Forty Years of Painting," opening Feb. 27 at the Hirshhorn, includes the oil on aluminum panel "Abstract Picture."Thomas Gainsborough's "Giovanna Baccelli," part of the first U.S. survey of the British painter's art.