The bullmastiff is a large breed of domestic dog, with a solid build and a short muzzle. The bullmastiff shares the characteristics of Molosser dogs, and was originally developed by 19th-century gamekeepers to guard estates. The breed's bloodlines are drawn from the English Mastiff and Old English Bulldog. It was recognized as a purebred dog by the English Kennel Club in 1924. They are quiet dogs, and very rarely bark.
Males should be 25 to 28 inches (64 to 71 cm) tall (AKC Std.) at the withers and 110 to 130 pounds (50 to 59 kg). Females should be 24 to 26 inches (61 to 66 cm) at the withers, and 100 to 120 pounds (45 to 54 kg). Exceeding these dimensions is discouraged by breeders.