Change civilization name/flag/leader every era, possible? easy? been done?

[Sanotra]

Is it easy and has it been done? Has anyone ever made a mod where civilizations change over time... aesthetically and in other regards? Currently the only thing I see that changes by era is the music, and the art of units and buildings. What I would like to do is to change things further. How difficult would it be to change, say... flags by era? Meaning, is it possible to change a civilizations flag every time they enter a new era? Is it possible to change the civilization's name by era? Their leader? That leader's traits?

These are all questions I ponder as I think about how to create a mod in which civilizations change over time. I'd like to see, "Northern Tribes" morph over time into "Russians". I'd like to see "Germanic Tribes" renamed in the industrial era to "Germany". "Celts" renamed mid game into "Ireland". "East Asian Tribes", into "China", and so forth. Each with a new flag and potentially a new leader (primarily for new traits). I'm not gonna ask if it's possible, because I'm sure it probably is. But is it easy and has it been done?

 

[The Capo]

I have something quite close to what you want happening in my mod. The flags change by era, and they can also change by leader and era as well. The colors don't change, nor does the name of the civ, but the flags do. Once I get a playtest ready for my mod I can send it your way, but I am not sure it will be easy to figure out.

 

[Sanotra]

In what way will it be difficult to figure out? That sounds great by the way!