The Sheltie's origins are obscure, but it is not a direct descendant of the Rough Collie, which it largely resembles. Rather, the Sheltie is a descendant of small specimens of the Scottish Collie and the King Charles Spaniel. They were originally a small mixed-breed dog, often only about in height at the shoulder, and it is thought that the original Shetland herding dogs were of the Spitz type, and were crossed with Collies from mainland Britain. In the early 20th century, James Loggie added a small Rough Collie to the breeding stock, and helped establish the breed that would become the modern Shetland Sheepdog.