The Pyrenean Mastiff originated in the Aragonese Pyrenees region of Spain andexperts believe the breed descends from anancient livestock guardian-type dog. This is a mountain breed, known for its size and protective instincts which make it such an effective livestock guardian.
Little is known about the exact origins or history of the breed but the earliest documentation comes from the Club de Mastin del Pirineo de Espana in 1977. It was only recently that the Pyrenean Mastiff was taken out of its native region and transported to other countries, like the USA. It is not yet recognized by the AKC, but it was recognized by the FCI in 1982.