For centuries, the Bedouin tracked the ancestry of each horse through an oral tradition. Horses of the purest blood were known as "Asil" and crossbreeding with non-"Asil" horses was forbidden. Mares were the most valued, both for riding and breeding, and pedigree families were traced through the female line. The Bedouin did not believe in gelding male horses, and considered stallions too intractable to be good war horses, thus they kept very few colts, selling most, and culling those of poor quality.