To commemorate the Spanish master's birth, Spain mounts shows in Madrid and Seville that offer fresh insight into his masterpieces and a rare look at lesser-known paintings

Spain has declared 1999 "The Year of Velázquez," honoring the 400th anniversary of the painter's birth with a series of celebratory shows. This month in Madrid, the Prado unveils its new Velázquez galleries. In mid-December, again at the Prado, "Velázquez, Rubens, and Van Dyck" will bring together the work of these three astonishing contemporaries. And this fall, in Seville, the Monasterio de la Cartuja will present the masterpieces that Velázquez completed in the Andalusian city of his birth, where he served as an apprentice to painter Francisco Pacheco (whose daughter he later married).

Velázquez was that rare being: a court painter whose work never stooped to flattery or the merely decorative. Soon after moving to Madrid, he found a position at the court of King Philip IV, where he rose steadily, becoming chamberlain before he died in 1660. But worldly success never diminished the depth and vigor of his work. Indeed, his portraits of the royal family penetrate to the very essence of his subjects.

Infanta Margarita conveys the tremulous decorum and painstakingly acquiredresignation of the little girl whose burdens include wearing a gorgeous but remarkably cumbersome dress. His successive portraits of Philip —from the full-length (circa 1624) rendering of the composed young king to the 1655-60 portrayal of a weary, saddened, jowly ruler—tell us less about the Spanish monarchy than about the effects of grief, age, and a lifetime of responsibility for which Philip was not, by temperament, ideally suited.

In the masterpiece Las Meninas—a work that still stuns with its originality—Velázquez's vision of the royal household expands to include intimations about youth and age, beauty and deformity, the complexity of human relationships, the miracle of art. The longer we look at it, the more clearly and deeply do we see, as our focus shifts from the girls in the foreground to the artist at his easel, gazing out at us from the canvas, and then to the mirror reflecting the image of the king and queen, whom the artist—dizzyingly, illogically—appears to be painting.

In part what's thrilling about viewing his oeuvre as a whole is the opportunity to marvel at Velázquez's versatility. His portraits range from macho noblemen mounted on rearing chargers to the elderly, hunched, brown-robed nun in Mother Jerónima de la Fuente, clutching (or is it brandishing?) her crucifix in a way that speaks volumes about 17th-century Spanish piety.

Velázquez's canvas Juan de Pareja is a portrait of his slave, who turned out to have his own talent for painting. The intelligence of his chosen subject's face is no more or less intense than the troubling blankness that the artist discovered in the distorted features of the dwarfs and buffoons whom he captured with a startling combination of sympathy and unsentimental accuracy. And all of his work is so haunting and so inexplicably moving: his depictions of everyday life (An Old Woman Cooking Eggs, 1618); his epic versions of biblical, historical, and allegorical scenes; the diminutive, melancholy landscapes painted during his journeys to Italy, such as the 1650 Villa Medici landscapes.

Velázquez seems to have been able to paint—with a few deft brushstrokes—anything he wanted. The luminosity of female flesh transfigures the Rokeby Venus; the sheen of armor, the flash of white lace, the gleam of black cloth, and the tracery of gold thread add to the magnificence of his royal portraits. Some of the best still lifes and animal studies ever painted appear, like grace notes, in his mythological and religious tableaux. Marvels of effortless harmony, his compositions invite us to admire how every seemingly insignificant detail is essential to the whole. However long we stare at Surrender of Breda, we cannot begin to figure out how its creator could render this complicated drama of armies coming together—soldiers, banners, horses, a hedge of pointed lances rising into the sky—so that every inch of canvas is lucid, perfectly legible, and buzzing with energy.

Four centuries after the birth of Velázquez, we can still feel his presence in the paintings, see his hand moving over the canvas, working magic with paint. I'd rush to take advantage of the welcome light that Spain and its museums are shining on his work. And yet it will always be the year of Velázquez. For spending time with his paintings (which invariably seduce us into allowing them plenty of time) gives the intoxicating sense that no effort has been wasted in the process of turning life into art.

Francine Prose writes frequently on art for the Wall Street Journal. Her latest book is Guided Tours of Hell (Owl Paperback).