[1] In medieval times, this dog accompanied the herds of sheep and goats crossing from northern to southern Spain, defending cattle from attack by wolves and other predators.

In 1981 the Asociación Española del Perro Mastín Español was formed, who organized a breeding program looking for the kind of large and strong mastiff of the past times, and drafted a new breed standard focused on recovering the old cattle dogs, fit as pets, and as guard dog and defense.

[1] The Spanish Mastiff may be a less-than-ideal pet in urban situations, where its booming voice and massive size could be problematic.

[citation needed] The breed is quite alert and food motivated but can bore easily; training must be consistent and firm but gentle.

[1] In addition to its considered "official" variety, which is the current and modern Spanish Mastiff framed in a rigid aesthetic pattern and recognized by the largest canine entities, there is also its more primitive, traditional variety, considered unofficial, that does not meet any aesthetic standards and has as its objective, still today, to serve its owners acting in the protection of flocks against predators.

These unofficial strains continue to act actively in their original and primitive function, with figures published by the World Wide Fund for Nature in 1986 showing a 61% reduction in predation of livestock when flocks are guarded by Mastiffs.