Because the Dobull-Mastiff is a very modern breed, documentation on their history is limited. However, we can go over his parent’s history. The Bullmastiff was first brought into the United States in the 1920s by oil tycoon John D. Rockefeller who wanted the large intimidating canine to guard his country estate. Developed in England around the 1860’s, the Bullmastiff is a cross between the Mastiff and the Bulldog. Gamekeepers bred these two formidable breeds to help them ward off poachers who wanted to gain access to the wild animals that were within the confines of estate. The Bullmastiff was known as the “Gamekeeper’s Night Dog” because he was agile, quick and strong despite his size and could run down and “detain” a poacher. It is believed that Mastiff-like dogs lived in Asia dating back to 2500 B.C. These dogs were used for hunting lions, fighting in the arenas and in war time. In the Roman Colosseum, they were matched against bulls, tigers, bears and lions. Julius Caesar wrote about the Mastiff-type breed in his account of invading Britain in 55 B.C. The Mastiff of today was developed in England over two thousand years ago. Bred to be guard dogs, they protected livestock from wolves and other predators. During the 1800s the Mastiff was used in cruel sports such as dog fighting, bear baiting and bull baiting. During World War I and World War II the breed almost became extinct; they were used as munitions carriers and were also hard to keep fed when food was scarce.