The world is full of populations of people who wish or demand that they had their own countries.
Think Taiwan, Tibet, and Crimea, for starters. But there are many more... enough to fill a book, it turns out. And that is Nick Middleton's An Atlas of Countries That Don't Exist.
There are examples you've heard of, like the three above. Many more will surprise you, like the Native American lands declared independent in the middle of the United States.