Jacques

Jacques is the French version of my name that means "supplanter" or "God may protect". The English name "Jack" is derived from the name Jacob and not from John. The sound of the two names is pretty much the same and many translations around the world demonstrate this right link. I personally don't believe in the result of Jankin = Jackin = Jack but in my studies I saw that often is: Jacob = Jacques = Jack. All dictionaries of English show this etymology.

I heard somewhere this was also the French form of John.