The Pyrenean Mastiff is a big size dog that has traditionally been being selected for flock guarding in the Aragonese seasonal migration system, which was completely different to that prevailing in Castile, ruled by the 'Honrado Concejo de la Mesta'.

   During centuries the Pyrenean Mastiff was the faithful companion of the flocks that went over hte pyrenean valleys and went down to the 'Maestrazgo' and even to Valencian land.  Seasonal migration routes in Aragon were short in comparison to those of Castile and Leon. Moreover, it often happened that there were different rules in every valley, depending upon customs or the masters criteria in the dominated land.  

   In any case, as time passed on and owed to a particular and functional selection, our breed became an essential part in Aragonese life. Thus, Pyrenean Mastiffs lived, killed and were killed next to shepherds, protecting their owner´s cattle and properties, which were always considered as their own by Pyrenean Mastiffs.

   However, very bad times came over for our great aragonese breed with the end of Spanish Civil War. Let´s think that it was a very difficult time economically and feeding a big size animal that practically had lost its primary function was a luxury that couldn´t be afforded easily. Because of that the Pyrenean Mastiff suffered a serious lost in its genetic inheritance, being mongreled in many cases and diminishing in number almost definitevely for its own survival as a pure breed. Fortunately in the middle seventies a very short number of enthusiastics of Pyrenean Mastiff set about the difficult task of recovering the Aragonese molosser starting out from individuals located in the country and that were very close in type to the traditional  seasonal migration Aragonese dog. With the Pyrenean Mastiff Club of Spain (CMPE) foundation in 1977 the basis for the beginning of our breed recovering were laid down.

    At the end of the twentieth century the Pyrenean Mastiff is a well known and respectful breed outside Spain. There are Pyrenean Mastiff Clubs in Sweden, Norway, Finland, Germany, Switzerland, Austria, Belgium, the Netherlands, Italy, France, Portugal, Czech Republic and United States of America. Our great breed did not deserve less than that. Its impressive appearance and excellent character are making our breed more and more appreciated outside Spain day by day and more prestigious in those countries where the Pyrenean Mastiff is first introduced.