The Domesday Book mentions ponies in Exmoor in 1086. At the end of the joint Hill and Darch wardenship of the Royal Exmoor Forest in 1748, all free-living ponies except agistered horses were removed from the moor and Forest. After that in 1767 Sir Thomas Acland I brought in a new herd of ponies and turned them out on the moor. Sales records of these horses in 1805 and 1809 list the colors black, grey, bay, dun, 'chasnut', and piebald. In 1818 nearly the entire moor was sold to John Knight. Sir Thomas Acland, the previous warden, took some of the horses to Winsford Hill, while others were sold. Starting in 1826, Knight crossed the remaining ponies with Arabians, Thoroughbreds, and other breeds to increase their size. It is said that the modern Exmoor pony descends from the Acland herd. By the late nineteenth century, the Exmoors were being selectively bred for the characteristic mealy muzzle. At first the Exmoor Pony Society accepted grey and black ponies in addition to bay, though the colour standards have been tightened since.