Tregonwell's Natural Barb Mare may have originally been owned by Mr. Tregonwell of Dorset (the maternal grandfather of the famous trainer Tregonwell Frampton, lthe Keeper of the King's Running Horses horses" [to William III, Queen Anne, George I and George II]). The term "natural" usually relates to a horse foaled in England from imported oriental parentage.

Horses descended directly in the maternal line from Tregonwell's Natural Barb Mare account for approximately 15% of the world's current throughbreds, the highest proportion of any Family.

She has three recorded foals:- Sister to Rockwood (by Place's White Turk) (1675c), through whom Family 1 descends; the colt Rockwood (1685c) [probably the same horse as Pulleine's Arabian and Pulleine's White Turk]; and a filly by Restive (1686c), 3rd dam of Bumper, a minor winner in 1740 and sire of the dam of the top class racehorse Antelope