There is much debate about the exact origin of the Newfoundland breed. Some people believe that they descended from a cross between indigenous Indian and/or Eskimo dogs and the Pyrenean Mountain Dog type (now the Great Pyrenees) that came to the Canadian coast with Basque fishermen. Others say that Newfies go back to ancient Tibetan Mastiffs that came across the Polar region with migrating tribes, or to dogs brought by the Vikings to North America. A careful survey conducted by a British naval officer in 1768 revealed that the Indian tribes of northeastern Canada had no native dogs of any kind. However, by the end of the 1700s, Newfoundlands were well-established in that region. British fishing vessels were common visitors to the Maritime Islands starting in the 1600s, and the sailors often usually brought dogs with them on their ships. Modern thought is that local fishermen started breeding small native Canadian dogs with the large European imports as soon as they arrived in their fishing ports. The Portuguese Water Dog and Great Pyrenees are still presumed to have been part of the mix, which ultimately led to the Lesser St. John’s Dog (which developed into the Labrador Retriever) and the Greater St. John’s Dog (which developed into the Newfoundland).