The pedigree of Costalero XV is one rich in the history of the Carthusian Horse. It is said that the breeding of the Spanish Carthusian horse began in the 1400’s via the Carthusian monks in Spain. Exactly how the monks acquired the horses is a mystery.

One popular theory starts with the Zamora brothers, who purchased a Stallion by the name of El Soldado, and bred him to two mares A colt and a filly were produced, and the colt, a dark grey, was named Esclavo and went on to become the foundation sireof the Carthusian breed.

Esclavo went on to produce many offspring, which were sold to breeders in Jerez. One group of mares sired by Esclavo around 1736 were sold to Don Pedro Picado, who then gave part of them to a group of Carthusian monks in the settlement of a debt and sold the rest to Antonio Abad Romero where they were absorbed into the main Andalusian breed.

The stock given to the monks was bred into a special line, known as Zamoranos, and specific breeding of the Carthusian horse was established by the 1400s.