This dog was developed from the old working Staffordshire Bull Terrier in the late 1800s and early 1900s. The Staffordshire Bull Terrier is believed to have descended from the two types of mastiffs of ancient times. The smaller of the two types was used to develop the Old English Bulldog and then it was crossed with terriers to create the breed known as the Bull and Terrier. The Irish Staffordshire Bull Terrier is rare today.