George Stubbs, an Englishman, is generally regarded as the greatest painter of horses in the history of art. For years he was considered a mere painter of animals for a small group of sporting clients. Indeed, for more than a century after his death, Stubbs (1724-1806) was nearly forgotten.

Due in large part to the advocacy and collecting efforts of the late American philanthropist and art connoisseur Paul Mellon, Stubbs was rescued from obscurity, and is now ranked not only as the best painter of horses ever, but as one of the most important British artists of the Eighteenth Century.

Painting with compassion and candor and building on his rough knowledge of equine anatomy, Stubbs created works that transcend the limits of sporting or animal art and reach the realms of great art. Nowadays, he is thought by many to be the equal of his better-known contemporaries, Thomas Gainsborough and Joshua Reynolds.

The English artist’s achievements in equine painting are showcased in “Stubbs and the Horse,” an exhibition organized by Malcolm Warner, senior curator at the Kimbell Art Museum in Fort Worth. It is currently on view at the Walters Art Museum through May 28. It concludes at the National Gallery in London, June 29-September 25. With 40 paintings, 35 drawings and three rare copies of Stubbs’ celebrated book, The Anatomy of the Horse, the show offers a once-in-a-lifetime opportunity to examine the range of the artist’s accurate and appealing equine images.

Little in Stubbs’ background indicated that he would become a great artist. Born in Liverpool, the son of a currier, he was essentially self-taught. While working as a provincial portrait painter in the north, he developed loftier ambitions.

Obsessed with anatomy, particularly of horses, he spent several years as a young man studying equine structure. He devised a means for mounting and dissecting numerous horse carcasses, which he then recorded in precise, detailed anatomical drawings. It has been said that the “subtle forms and modeled curves and planes in a [horse] skeleton were to George Stubbs what a symphony is to a musician.”

After a brief sojourn in Italy in the late 1750s, Stubbs moved to London, where he lived the rest of his life. He taught himself how to engrave in order to illustrate his pioneering text, The Anatomy of the Horse (1766). The definitive work on the subject up to that time, it gained international acclaim and is still highly regarded by horse experts. It is a special treat to view three copies of Anatomy in the current show.

Fortuitously, Stubbs’ arrival in London coincided with a great burst of interest in the breeding of horses and their participation in hunting and racing. Horse racing, which had become popular toward the end of the Seventeenth Century, was organized and developed an even greater following with the founding of the rule-setting Jockey Club around 1750.

The sporting aristocracy on their country estates came to equate ownership of horses as second only to the ownership of land. It followed, as one art historian put it, that “After portraits of himself, his wife and his children, the English patron of the Eighteenth Century liked best to have a picture of his horse.”

Stubbs soon received commissions from noblemen and wealthy country gentry to paint their favorite mounts. Eventually, his equestrian work made him one of the best-paid artists in Britain.

His work was particularly popular because of his ability not only to depict horses with accuracy and personality, but because of his skill at portraying individualized human figures and grand landscapes. Stubbs’ scenes of life in rural England and around racecourses are filled with charm and nostalgia.

The highlight of the exhibition is an enormous – 115 by 97 inches – portrait, “Whistlejacket,” 1762. From the collection of the National Gallery in London, this spirited likeness was originally intended as the basis for an equestrian portrait of King George III. The horse’s owner, the Marquis of Rockingham, who commissioned the work, was so pleased with Stubbs’ depiction that he wisely took it as it was. A rarity in its day for focusing solely on a horse, it is an unforgettable masterpiece.

Stubbs also executed a series of group portraits of horses and foals, with no humans in view, like “Mares and Foals,” 1763-65. Showcasing the painter’s mastery of design and his aesthetic touch, these are enduringly beautiful homages to the forms of horses, whether depicted in parklands, beneath sturdy oaks or on riverside meadows.

Another masterwork, “Gimcrack on Newmarket Heath, with a Trainer, a Stable-Lad and a Jockey,” 1765, features a superb portrait of a famous colt, the victor in numerous races, standing in front of a rubbing house and being attended by handlers. Gimcrack also appears in the right background, under an expansive sky, winning a race, presumably at the famous Newmarket racecourse.

Stubbs is especially admired for the unusual accuracy and appeal with which he portrayed the rippling musculature and regal stance of his equine subjects. The physique and nobility of the steed is emphasized, for example in “Lord Grosvenor’s Arabian Stallion, with a Groom,” 1766-70.

The artist’s series of works showing the spectacle of lions attacking horses was apparently inspired by Hellenistic sculpture he had seen in Rome, augmented by the popularity of scenes of danger, terror and fear as manifestations of the sublime. His large canvases and enamel on copper images, among his best-known works, explore various stages of nightmarish tooth-and-claw encounters.

In highly dramatic compositions Stubbs showed the stealthy approach, the victim’s fear and the fury of the assault. “A Lion Devouring a Horse,” 1769, conveys the savagery of the ferocious attack on a white horse. These are memorable images.

In the 1790s the Prince of Wales (the future King George IV), an avid horseman, became a major patron, commissioning Stubbs to create some of the most poetic compositions of horses and horse people. “The Prince of Wales’s Phaeton, with the Coachman Samuel Thomas and a Tiger-Boy,” 1793, stars two beautifully matched horses being readied for a drive of their master’s carriage.

The stateliness of the horses in the face of the distractions of the leaping, barking dog, matched by the stolid composure of the State Coachman, resplendent in his scarlet and gold trimmed coat, adds to the appeal of this fine canvas.

Also from The Royal Collection (of Queen Elizabeth II) and commissioned by the Prince of Wales is a spirited equestrian and human portrait, “Lady Lade,” 1793. It immortalizes the royal’s friend, an accomplished rider, who was better known for her scandalous behavior and bad language. The depiction of her atop a rearing horse suggests her ability to control a rambunctious mount.

Stubbs was by all accounts a straightforward, determined, curious, energetic and unsociable person. Stubbs’ self-portrait of 1781, executed in enamel on a Wedgwood earthenware oval, shows him, at 57, as a pudgy gentleman with strong features holding a paint brush in a delicate hand.

The breadth, depth, accuracy, beauty and aesthetic quality of Stubbs’ equestrian works are evident throughout this rewarding exhibition. “Stubbs and the Horse” effectively documents how the artist’s canvases raised sporting art to the level of high art.

The 229-page exhibition catalog contains useful essays and 110 color and 131 black and white illustrations. Published by the Kimbell Museum in association with Yale University Press, it sells for $55, hardcover, and $29.95, softcover.

The Walters Art Museum is offering a wide range of programs for adults and children in connection with “Stubbs and the Horse.”

The museum is at 600 North Charles Street. For information, 410-547-9000, ext 23, or www.thewalters.org.