"Arabian horses are the foundation ancestors of our beloved Thoroughbreds. - ME. Altieri" Did you know that every Thoroughbred, in order to prove they are indeed a Thoroughbred, must prove they can trace their lineage back to one of three foundation Arabian sires? Author Marion Altieri outlines the immense impact Arabians have had on the entire racing industry. From the Dubai World Cup to Saratoga Springs, Marion Altieri has been at the rail documenting this breed's continuing legacy.