The Rambouillet breed is also known as the Rambouillet Merino or the French Merino.
Today's Rambouillet sheep has a royal pedigree. The breed originated in Spain. The Spanish Merino flocks were renowned from the earliest times as producers of the world's finest wool. The Spanish government forbade any exportation of the precious sheep.
In 1786 however, Louis XVI of France purchased Spanish Merinos (318 ewes, 41 rams, and seven castrated rams or "wethers") from his cousin, King Charles III of Spain. The new French flock was then developed on an experimental royal farm about 50 km southwest of Paris, the Bergerie Royale (now Bergerie Nationale) in the king's domain of Rambouillet. The flock was raised exclusively at the Bergerie, with no sheep being sold for several years, well into the 19th century.
"Outcrossing" with English long-wool breeds and selection produced a well-defined breed very close to the Rambouillet of today, differing in several important points from the original Spanish Merino. The overall size was greater, with full-grown ewes weighing up to 200 pounds and rams up to 300 pounds. The wool clips were more plentiful. The fleece staple length varied from two to four inches and came to range in fiber diameter from 18.5 to 24.5 microns or 60 to 80 for the numerical count. (To put that in perspective, a human hair is 75 microns, and the best varieties of cashmere have a micron count of 14 or less.)
Eventually, other French Merino sheep were introduced into Germany during the last quarter of the 18th century, and German breeders made extensive use of Rambouillet sires as the sheep's fame spread throughout Europe.
In 1889, the Rambouillet Association was formed in the US with the aim of preserving the breed. Today, an estimated 50% of the sheep on the US western ranges trace back to the French Rambouillet flocks, or the German von Homeyer flocks. The breed today is well known for its high-quality wool, and also for its meat. It has been described as a dual-purpose breed, with superior wool and near-mutton breed characteristics.
One special yarn at Avenue Yarns created from 100% Rambouillet wook is Vale from Brooklyn Tweed.