Ah you are all so eager for a large-scale map.. I really appreciate Helges effort, and I think for now we should not even go beyond the british islands. We can always increase the scale if things go very well. But since any battles we can recreate would only be small scale anyway I would rather aim to keep things in a rather small region for now. And one that is quite well documented is the south-east of england, around the Sussex and Kent area.
We even have this map (which portrays a later stage though) which shows the most important places at the time shortly after the norman conquest:
If we just take every of the more important places we could set up quite a bit of connected terrain already. Many of the places named here can be investigated quite succesfully, and if you think about it we already have three maps of these, namely Romenel (old romney, Eorpeburnan, which supposedly was a burgh roughly between Hawkhurst and Headcorn, and Essetesford, which is of course Ashford and was played in the event last weekend.
For Canterbury, Rye, Wye and Appledore there are sources too, as well as for Great Chart (near Ashford) and Dover. With the setting of our last event Canterbury could be pretty much the final siege of an entire campaign, and we even have sources of the walls structure safely on my harddrive.
I think a small-scale campaign like this would feel much more "alive" than having a king of norway cross the sea with four rather confused allies, landing at an undefended coast until finally defeating the two-man strong english army in a pitched battle and claiming a randomly put together London with three houses and a shed inhabited by three cats for himself.
Now the next step for this would be gathering sources for each place, pinpointing them on a map, and asking for mappers to get started on them. Each could have a set of filtered sources and maybe an overview map. I know how much effort it is to do both, so if we split it more people can help, and it will be more easy for people.
To me this seems far more likely to succeed than any more large-scale plans, but still your work is not in vain, Helge, but you could simply try to "zoom in" on this south-eastern part and maybe draw a more neat version of this cinque port map I have further upwards in my post.
But with this post I don't want to dictate you this course, but rather recommend this way, and I can just hope most of you agree with it, with all the advantages it brings.