Westies are descended from Cairn Terriers, who occasionally whelped white puppies naturally, and Scottish Terriers; who also occasionally produced white offspring. White offspring from other British Terriers such as the Bedlington Terrier were occasionally introduced to the bloodline for desired characteristics, but this practice generally stopped in the 1850s. Some sources credit Colonel Malcolm and his kin of Poltalloch, in the Argyll region of Western Scotland as the originator of this breed in the 1800s. Other sources credit the Duke of Argyll (Chieftan of Clan Campbell) as the originator of the breed. It may have taken as long as a hundred years of selective breeding to produce all the desired qualities. Their white coat made them highly visible when hunting on the Scottish moors and easily distinguished them from their game. They also possess keen intelligence and a sturdy frame. Originally the breed was known as Poltalloch Terriers, although they were also known as Roseneath Terriers, White Roseneath Terriers, and at the end of the 19th century, briefly as a white variety of the Scottish Terrier.