The Great Pyrenees' origin is lost to the ancient mists of time long, but there are many ancient writings that note the dog at length. This breed is thought to have come from sometime between 1800 and 1000 B.C. One of the first documented mentions of this mountain sheepdog is the Roman author Varro. In his "De re rustica" (written in 37 B.C), he wrote that the dogs were essential for guarding livestock and described the dog. He also noted that the dog's white coat made it easy to distinguish from wolves and other predators at night.
The history of the Great Pyrenees was one that may have been taken for granted for some time after Varro's observations. Toward the end of the middle ages, however, the dog was again observed in detail and a number of records exist from those centuries. In the 15th century, French writings describe the breed and its uses. These large dogs had long been appreciated by shepherds whose work in the mountains was treacherous in many ways. The French aristocracy had taken a liking to the dogs and the breed became favored by The Grand Dauphin. They were initially known as around the Chateau of Lourdes as guardians. While serving King Louis XIV, Dauphin decreed them as the Royal Dog of France in 1675. This made the dogs very popular and highly sought by French nobles.
By the 17th century, the dogs had been exported to Newfoundland. They were cross-bred with black English Retrievers, and the result was the Newfoundland Landseer dog. In the early 19th century, the dogs were introduced to the United States by the French general, Marquis de Lafayette. He delivered two of the dogs to an American author, J.S. Skinner, who later mentioned the dogs in his 1845 book, "The Dog and the Sportsman."
It took nearly another century, to 1933, before the American Kennel Club formally recognized the breed.