This mod has all of the official factions in it including the Burgundians and Swiss. It is set late in the High period, and has far too many changes to list. I used an Historical map in making it, but foremost in my mind was to create a challenging game (for any faction), now taking and holding neutral provinces is a bit (sometimes a LOT) harder. I think it results in a more challenging, realistic game with stategy and politics being more import, as opposed to conquering everything in sight.
Included is a smaller version of the map I used (the original is 3 MB).
Installation.
Just copy the 1275EuroCityStates.txt file into your Medieval Total War\campmap\startpos
folder. To remove it, just delete that file.