The mastiff is the prototypical breed of the ancient mastiff group of dogs. The confusion between the mastiff breed and the mastiff family makes it very difficult to trace the history of the breed. Even though the mastiff family is one of the oldest and most influential, the breed is undoubtedly of more recent, though still ancient, origin. By the time of Caesar, mastiffs were used as war dogs and gladiators. In medieval times, they were used as guard dogs and hunting dogs and became so widespread as to become commonplace. Mastiffs later stepped into the arena of dog fighting, bull-baiting and bearbaiting. Even when these cruel sports were banned in England in 1835, they continued to be popular events. The modern mastiff descends not only from these pit dogs but also from more noble lines, being descendants of one of the most famous mastiffs of all time: the mastiff of Sir Peers Legh. When Legh was wounded in the battle of Agincourt, his mastiff stood over him and protected him for many hours through the battle. Although Legh later died, the mastiff returned to his home and was the foundation of the Lyme Hall mastiffs. Five centuries later the Lyme Hall mastiffs figured prominently in founding the modern breed. Some evidence exists that the mastiff came to America on the Mayflower, but the breed’s documented entry to America did not occur until the late 1800s. The breed was nearly decimated in England by World War II, but sufficient numbers had been brought to America by that time to keep the breed going. Since that time, it has gradually risen in popularity.
Animal Planet. (2013) Mastiff Guide. Retrieved from http://www.animalplanet.com/breed-selector/dog-breeds/working/mastiff.html