Behold: Insularis Draco! An overhaul of the 2014 gem 'Invasio Barbarorum II: Conquestus Britanniae'. 30 playable factions, four (!) immensely detailed maps of North-Western Europe, covering the period of 355-700 A.D. when tribal migration, plague, climate change and all-out war spelled an end to Antiquity and a new world of 'barbarian' kingdoms rose from the ashes of Empire. The Dark Ages have descended upon the West. 'Times of great trouble and uncertainty offer substantial opportunity, but it is reserved only for those who dare to grasp it. Who will be Bretwalda and who will be Insularis Draco?' Greetings from the modding team (Urbgen, Benfras, Belovèse and PythagoreanBeans) working every day to improve I.D. for you! If you want to test it and give us feedback you can join our Discord (find the Homepage link)
Most ex-Roman settlements in Gaul, Belgica and Germania now have an alternate name for when they revolt or are re-conquered by their erstwhile Imperial overlords. Just see what happens when the Alamans leave the Upper Rhine region.