The Scots and the Norse would ferment buttermilk (whey left over from making butter). In the north of Scotland this was still done to the early part of the 20th Century. The wine was very low alcohol (about 2-3 %) and was called blaand (as in blond, not bland). and was carried in kegs by fishermen and crofters. I have heard an old recording of someone talking about their memory of blaand telling the anthropologist who was interviewing that blaand was both the very first drink a baby would know - yes, before it tasted its mother's milk, and was the last taste the dying would know before they passed away. When dairies replaced cottage industry blaand was forgotten but it is slowly, slowly making a comeback and I see that there are now a few distilleries that specialize in using whey as their "mash or "wash". Not sure if they transform the lactose into glucose by adding lactase (there is about 20 points of gravity in my whey.. or they simply add sugar to the whey and ferment ON the whey - for flavor - and then distill that wine. (I add about 2 lbs of sugar to the whey after I have a) boiled it to stop any additional bacterial activity changing lactose into lactic acid, and b) after I have added about 5 lactase tabs to convert the lactose.
In the Urals, folk still ferment horse's milk . That's called khumis.