The Yorkshire Terrier is a small dog breed of terrier type, developed during the 19th century in Yorkshire, England, to catch rats in clothing mills. Ideally its maximum size is 7 pounds (3.2 kg), although some may exceed this and grow up to 15 pounds (6.8 kg). It is placed in the Toy Terrier section of the Terrier Group by the Fédération Cynologique Internationale and in the Toy Group or Companion Group by other kennel clubs, including the American Kennel Club. A popular companion dog, the Yorkshire Terrier has also been part of the development of other breeds, such as the Australian Silky Terrier. It has a grey, black, and tan coat, and the breed's nickname is Yorkie.