The Yorkshire Terrier (often shortened to Yorkie) is one of the smallest dog breeds of the terrier type. The breed developed during the 19th century in Yorkshire, England. A popular companion dog, the Yorkshire Terrier has also been involved in the development of other breeds, such as the Silky Terrier. Most have a black and tan coat, but they are also known to have a silverish-grey or a blonde coat. Yorkshire Terriers are very playful and energetic dogs. Some people who have a Yorkie as a pet have two, because they often have separation anxiety when left alone.