Bullmastiffs are intelligent, alert, and calm. In combination with their large size and speed, these traits made the Bullmastiff breed well suited for its original use as a guard dog against poachers. Dog sports such as agility, tracking, carting, rally obedience, and traditional obedience as sport can provide physical and mental stimulation while strengthening the dog's bond with its family. Their reputation as a good family dog allows them to be around children; however, as with all dogs, extremely close supervision is needed to prevent accidental injury to the child or dog and avoid the dog's subsequently developing any fear-based defensive aggression.
The history of the Bullmastiff dates back to the mid-nineteenth century when English estate owners found themselves in need of a guard dog that would protect their properties from poachers. Breeders began crossing English Bulldogs with Mastiffs and the Bullmastiff is a result of those efforts. The goal of the breeders was to develop a powerful breed that would be capable of knocking down an intruder and holding that intruder to the ground until its master arrived. The efforts were successful and the Bullmastiff was so good at its job, it was often referred to as the gamekeeper's night dog. The American Kennel Club officially recognized the Bullmastiff as a breed in 1933.