The Bullmastiff is a large-sized 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 the extinct 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.