The Mastiff's Origins and History Source: Wikipedia. Country/Region of Origin: modern breed: England; original origins uncertain Original purpose: herding, guard dog Name: Also called the English Mastiff or Old English Mastiff. The name Mastiff also refers to a large family of large dog breeds. Another name for Mastiff in the general sense is molosser. Historical notes: the origins of the Mastiff are not certain, though carvings depicting the animals have been found in Assyrian Ninevah dating back to around 640 BC.