 Dr. Ruy d 'Andrade gave the breed their name of " Sorraia " . D 'Andrade took the name from the Sorraia River in Portugal . The breed had previously been known by the local Portuguese as " <unk> " or " zebra " , due to their markings . In the time of Christopher Columbus , the Sorraia was also known as the Marismeño , but the Sorraia and the Marismeño have evolved into two different breeds over time . Today , the name Marismeño refers to a population of <unk> horses living in <unk> Natural Park in Spain . 
