Alcock's Arabian (foaled c.1707, died c.1733), also known as Pelham Grey Arabian and possibly Bloody Buttocks and Ancaster Turk among others, is the ancestor of all grey-coloured Thoroughbred horses, as well as grey sport and riding horses descended from Thoroughbred lines. It was said he was imported into the Kingdom of England early in the 18th century. However, there is no firm evidence to support this assertion. There is, however, strong evidence that he was a son of Curwen's Bay Barb out of Old Wen Mare (Sister to Clumsey). The Old Wen Mare was either full sister or possibly the same mare as the exceptional broodmare Grey Wilkes. Volume 1 of the fifth edition of the General Stud Book lists Sir W. Wynn's Spot - a horse accepted to have been sired by Alcock's Arabian, as: "...by a son o