La Monteria Infernal - The Infernal Chase

"The forebears of these dogs, and their handlers, had learned the aet of 'la monteria infernal' the infernal chase, in the Canary Islands in 1480, when they literally ran to ground, maimed, killed, and devoured the natives. But the fell beasts were even better known for feasting on children abandoned at the doors of churches and mosques by their desperate parents during Ferdinand and Isabella's successful campaign to seize Granada from the Moors. That victory came just months before Columbus's first voyage; a few of these dogs or their offspring were doubtless on his second trip.
Spain at that time was fixated on the concept of blood purity, limpieza de sangre, which its soldiers and priests applied to humans as well as animals... The same concept was applied to breeding livestock, horses, and dogs - labrel, a fast chase dog sometimes associated with a greyhound; mastin, or mastiff; sabueso, a bloodhound; and alano or wolfhound, a rough combination of the two types - with different monasteries and nobles maintaining their own lines. These divisions were based on size, coat coloration, and use: by tradition, light-colored mastiffs were used to guard flocks, in the belief that they would not scare the sheep, and dark-colored ones to guard homes and to fight, because they terrorized people. They were not 'breeds,' as they are known today, divided by registries and close adherence to standards.
"A Dog's History in America, Mark Derr
The dogs of pursuit, Pero de Presa, were of the Alaunt Ventures type of crossbred dogs used for the "Kill" of big game, while the light-colored mastiffs used guarding livestock were of the Pero de Ayuda, Alaunt Butcher's type used by herdsmen of cattle, ect. This is what sets the White English apart, used by farmers to defend livesock and especially children, as defense aka guard dogs, they are void of the chase. Void of aggression. Void of fear.
"Every geneticist knows that the hereditary traits for fearfulness and extreme aggression lie closely bound together."The Technique of Breeding Better Dogs, Dr Dieter Fleig