The original Belgian Mastiff of the middle ages is believed to be extinct but a certain group in Belgium is trying to re-create the Belgian Mastiff according to the standards of the breed. A large and massive breed, the original Belgian Mastiff was used popularly for heavy workload like pulling carts and guarding farms. The breed was devoted to its owners and kind and affectionate to children but aggressive towards strangers and other dogs. A distinguishing feature of the breed was a bob-tail. Primarily a working dog, it was also used during the first World War by the army to pull arms and ammunition carts as well as for transporting wounded soldiers. Not many Belgian Mastiffs survived the war and the number decreased significantly.
The breed had a large head that was not very broad. The eyes were set deep with black or brown colour. Medium length ears were level with eyes and nose was black with wide and well tapered muzzle. The neck was thick and well-muscled. Chest was deep and with well sprung ribs. Body had powerful back and loins. Forelegs were set apart and straight while the hind legs were strong, muscular with hooks well let down. Feet was strong and compact and tail was bob-tail. The body helped the massive animal in strong movement and agility.
The Belgian Mastiff had height and weight between 25-32 inches and 90-115 lbs respectively. This breed was NOT recognized by AKC.