Four years ago I was thinking of writing a timeline about a Belgian revolution in which Belgium was divided by France and the Netherlands (which is why Brussels and Louvain are French). I believe the result was a Franco-German cold war during the 20th century, but after thinking about it I decided against writing it. This probably was one of those threads I posted will considering it. I think if you look at other threads around the same time you'll find more. Currently I have no plans about writing it anymore. Why someone bumped it since than, I am not sure, but it is interesting to see one of my old threads.Charlemagne's german was probably closer to old Dutch than old German.
I'm not sure where your going on this thread. Are you making a time line where Dutch is spoken much more widely?