This is my second favorite breed of domestic cats, The British Blue Shorthair.
Julius Ceasar brought these cats to the British Isles on his ships, because they are a stocky fighting type breed of cat and they are excellent mousers. Yes they are a fighting cat, my neighbor had one called Shadow. He was the terror of the neighborhood and would even chase the dogs, the dogs run from this cat.
So when Julius Ceasar landed on the British Isles these cats jumped off the ships and took over.
There is a cat in France that looks exactly like The British Blue Shorthair, not quite as stocky.
The Monks in France had these cats in their grainerys to catch the mice. These are called the Chartruese. There is a lot of discussion and controversy among Cat Fanciers that these are the same breed and each country claims this cat as it's own.
Shadow used to come over everyday for visits, he jump up on the ledge of my kitchen window and look in. Then he see me and he go Meow. So I go to the door and let him walk in, and he walks in like a gentleman and is nice to my female cat and jumps up on the shelf and watches everything.