The English Mastiff, referred to by most Kennel Clubs simply as the Mastiff, is a breed of large dog perhaps descended from the ancient Alaunt and Pugnaces Britanniae, with a significant input from the Alpine Mastiff in the 19th century. Distinguishable by enormous size, massive head, and a limited range of colours, but always displaying a black mask, the Mastiff is noted for its gentle temperament. The lineage of modern dogs can be traced back to the early 19th century, the modern type was stabilised in the 1880s and refined since. Following a period of sharp decline, the Mastiff has increased its worldwide popularity. Throughout its history, the Mastiff has contributed to the development of a number of dog breeds, some generally known as Mastiff-type dogs, or, confusingly, just as "Mastiffs" . With a massive body, broad skull and head of generally square appearance, it is the largest dog breed in terms of mass.