I had to look that up mate.
Interesting fact of the day. The traditional Cumberland sausage is said to be a localised version of the German sausage that the many German lead miners, who immigrated here to dig in the Cumbrian mountains, brought with them.
I should really have mentioned it as a favourite dish too. Don't be fooled by commercial 'Cumberland' sausage available in supermarkets. That's usually rubbish.
Proper Cumberland sausage has to be at least 98% meat. The rest being herbs and spices. It should also by rights only be called Cumberland sausage if it is made within this county.