English, as a language, is basically made up of a Germanic base with French icing. This is because England was settled by the Angles (hence Angle-Land or England) and Saxons, Jutes etc. Then, it was invaded by the Normans.
But what if it hadn't been? What if the Normans had lost the battle of Hastings. What would the English language look like?
Obviously, it's a bit of a silly question as all sorts of other things might have happened or not happened and so on and so forth. Nonetheless, it's a fun idea to muck around with, and somebody has been doing exactly that.
For reasons unknown to me, somebody appears to have been re-writing Wikipedia using only words of Anglo-Saxon origin. It's fantastic: not simply because it's a fascinating linguistic feat, but also because any writing that follows a strange rule ends up being a good read.
For example, in the article on the history of the USA (or Banded Folkdoms of Americksland) you have people moving westward in search of "thrivedom" and a war of "Lonestance". Anyway, I thoroughly recommend that you read it. Link here.
Incidentally, there was a movement in the nineteenth century called The New Philology that attempted to purify the English language in just this way, I'm glad to see that somebody has now carried it to doneness.