The Airedale Terrier (often shortened to "Airedale" or "ADT") is a breed of the terrier type, originating in Airedale, a geographic area in Yorkshire, England. It traditionally was called the "King of Terriers" because before the creation of the Black Russian Terrier by the NKVD, the Airedale was largest of the terrier breeds. The breed has also been called the Waterside Terrier, because it was bred originally to hunt otters in and around the valleys of the River Aire which runs through Airedale. In England this breed has also been used as a police dog.