Mastiffs: "As a lion is to a cat, so is a mastiff compared to a dog."
A very old breed, Mastiffs were depicted in Egyptian monuments as early as 3000 BC.
It is believed that a Mastiff came to America on the Mayflower.
One of the most famous mastiffs of all time [besides my avatar!]: the mastiff of Sir Peers Legh. When Legh was wounded in the battle of Agincourt, his mastiff stood over him and protected him for many hours
through the battle.
Mastiff are a foundation breed and many other breeds wouldn't exist without the Mastiff lineage. Some of these include:
Tibetan Mastiffs:
For scale purposes (and because I would like to be that guy!):
Neapolition Mastiffs: (If they didn't drool so much, I'd get one!)
Leonbergers:
Boerboel, or South African Mastiff:
Tibetan Mastiffs: (If they didn't shed so much, I'd get one!)
Mee Kyun Dosa (or Korean Mastiff):
St. Bernard:
Spanish Mastiff:
Great Dane:
Great Pyrenees:
Newfoundland:
Dogue de Bordeaux:
Greater Swiss Mountain Dog:
Bernese Mountain Dog:
Bullmastiff:
Cane Corso:
Dogo Argentino:
Rottweiler:
Komondor (or as my kids like to say, the mop dog (along with the Puli):
Boxer:
Bulldog:
French Bulldog:
There's more but that's a pretty good sampling (forgive me if I neglected to mention your favorite breed!). So the easiest way to guesstimate if a breed is decendant from Mastiffs, answer one question: "Are they small and yippy?" If not they owe it all to Mastiffs! 