Darley Arabian
Flying Childers was sired by the great Darley Arabian, one of the three foundation stallions of the thoroughbred breed. His dam Betty Leedes, was by (Old) Careless and she was inbred to Spanker in the second and third generations (2x3). Betty Leedes was also the dam of the unraced, but successful sire, Bartlett's or Bleeding Childers who was also by the Darley Arabian. (Old) Careless was by the great stallion Spanker, and both were thought to be the best racehorses of their generation. Betty Leedes was one of the few outside mares allowed to breed to the Darley Arabian, who was mostly kept as a private sire by his owner.