The Newfoundland shares many traits with other Mastiffs, such as the St. Bernard and English Mastiff, including stout legs, massive heads with very broad snouts, a thick bull neck, and a very sturdy bone structure. In fact, many St. Bernard Dogs have Newfoundland Dog ancestry. Newfoundlands were brought and introduced to the St. Bernard breed in the 18th century when the population was threatened by an epidemic of distemper. They share many characteristics of many mountain dog breeds such as the Great Pyrenees. The Newfoundland breed originated in Newfoundland, and is descended from a breed indigenous to the island known as the lesser Newfoundland, or St. John's dog. The Mastiff characteristics of the Newfoundland are likely a result of breeding with Portuguese Mastiffs brought to the island by Portuguese fishermen beginning in the 16th century.
The speculation that Newfoundlands may be partly descended from big black bear dogs introduced by the Vikings in 1001 A.D. is based more in romance than in fact. By the time colonization was permitted in Newfoundland in 1610, the distinct physical characteristics and mental attributes had been established in the Newfoundland breed. In the early 1880s, fishermen and explorers from Ireland and England traveled to the Grand Banks of Newfoundland, where they described two main types of working dog. The breed's working role was varied. Another famous all black Newfoundland performed as the star attraction in Van Hare's Magic Circus from 1862 and for many years thereafter in one of England's founding circus acts, traveling throughout Europe.
The breed prospered in the United Kingdom, until 1914 and again in 1939, when its numbers were almost fatally depleted by wartime restrictions. Since the 1950s there has been a steady increase in numbers and popularity, despite the fact that the Newfoundland's great size and fondness for mud and water makes it unsuitable as a pet for many households.
William Withering, famous for his book on the use of Dropsy published in 1785, lived at Edgbaston Hall, Birmingham between 1786 and 1799. While there, he bred Newfoundland Dogs. There is very little else on his experiments with these dogs. His daughter Charlotte married a Beriah Botfield and they had a painting in Norton Hall by Samuel Cox of Daventry painted about 1830-1840 called "Portrait of Lion, a Newfoundland Dog, and Juba, a Pug Dog of Mrs. Botfield's. This hung in the north front of Norton Hall. This painting would have been made around the same time that Landseer painted his portrait of Lion, the Newfoundland Dog. (See 'Catalogue of Pictures in the possession of Beriah Botfield esq.at Norton Hall' published in London in 1848.