Dragonflow
Emperor
Everyone else is tired of repeating this, but as far as Firaxis is concerned it is, and always has been. The only times they've ever broken the rule that two civs with a shared history can't be included are the Holy Roman Empire (with Germany) and Gallic Celts (with France).
It's actually more like they did it only once with the HRE. Gallic Celts have almost nothing to do with the French who are of Frankish decent AFAIK.