The Heirloom taproot horses are those Al Khamsa Foundation Horses and their predecessors exported from Arabia Deserta before 1914 from which the Root Mares and Root Stallions of the Royal Agricultural Society of Egypt descend, as recorded in the first volume of the RAS Studbook. Heirloom Egyptian Arabian horses therefore encompass only the oldest Egyptian bloodlines in Al Khamsa, the Egypt I and Blunt ancestral elements, without admixture of later blood.

Today, there are an estimated 850 living horses tracing only to these sources, upon which the RAS based its purebred breeding program. Heirloom Egyptians are owned and cherished by many farms in the U.S.A. and throughout the world.