The Bullmastiff was specifically bred to bring down a man without biting him and hold him until his Master arrived. In the 1800s the estates of Great Britain suffered serious losses from "poaching" or the stealing of livestock and game and the Bullmastiff was bred to assist in eliminating poachers. This is a big dog, with a big attitude, but was not bred to attack but rather to hold at bay. The original cross of bull dogs with mastiffs produced this tractable yet powerful breed. The foundation stock was 50% Mastiff and 40% Bulldog. The common known term name for the breed early on was "The Game-keepers Night Dog". At first this was a rather generic description for all the big dogs that patrolled the estates but gradually these original dogs were more selectively bred and became what is today known as the Bullmastiff.