The Welsh Terrier is descended from two now-extinct breeds: the Black and Tan Terrier and the Old English Terrier. This two breeds had existed in Wales and England as far back as the thirteenth century. By the eighteenth century, these two breeds were so similar, that they were designated as the same breed. While there was a brief effort by the English to name the dog the Old English Broken Haired Black and Tan Terrier, the Welsh got their way and they were called the Welsh Terrier. Used much like other terriers in hunting fox, otter, rabbit and badger, they also performed vermin extermination duty. Later, these dogs were crossed with the Fox Terrier, resulting in the modern Welsh Terrier.
The most well-known Welsh Terrier was probably Charlie, who belonged to President John F. Kennedy.