This race is a prolific producer of wool and, for this reason, it became one of the mainstay of the Spanish economy for many years. The merino shepherd was the one who took care of the flock, of its pastures and divisions. The main one of these was nominated by the king, in a territory, where he had a considerable jurisdiction. He then took care of nominating the minor merinero and, finally, there was the baby merinero.
The territory under him was called "merinidad". It consisted of a district , with a city or an important town that defended or took care, the interests of the people and the farmers, located in its area. That shows the great importance of the transhumance within the Spanish society. The "merineros" dog were those taking the merino flock. There were three types of dogs: the guiding one, the gathering one and the Mastiff, or dog of iron, as poetically called in the novels.
The last one were in charge of defending the flock from the attack of the main predator of that time: the wolf. A precisely defined function and, an ideal contest where to perform it : the routes of transhumance. The Spanish Mastiff is a race that automatically selected itself at work.
It could be affirmed that the real judge, in the selection of such Mastiffs was the wolf itself! It had to be a very strong dog, tireless, that after having taken the flock for the entire day, had not to hesitate, not even for one second in front of a predator's attack.
Therefore the dog used to defend the sheep, without showing any tiredness, acting with intelligence and tenacity. A fair food reward was reserved to it, made of lard or dark bread.
During the time of the Mesta, the people of Burgos was obliged to feed the Mastiffs before themselves. The dog with the iron collar, represented for the flock and the community a great safety and, in the case that, it had committed a mistake terror and danger would have arrived. Nowadays are also relevant, the flocks that move on international territories, being Spain, one of the major European producer of wool.
Therefore the Mastiff of the flock, even if decreased in number respect to the Gold Century, continues to be necessary; that is made evident also by the measures taken by the E.C in favour of the extensive sheep farming and the protection of the mountain areas and the fields particularly widespread in Spain. The flocks of sheep are still seen in the Spanish fields and with them also the dogs: the guiding one and the Mastiffs. The Mastiff was born in the fields and in them it continues to live.