Age of Civilizations Wiki

Civil wars are sort of like rebellions but a lot more powerful, there isn't too much information out there so Im giving information from my top 4 experiences with them.

Civil wars can happen randomly but from my experience happens either from a set scenario set by a player or when a nation is being swept over by a bigger enemy in a war.

When I was playing as Serbia in modern world, India was losing a joint war against Pakistan and Myanmar. When the capital fell and most of the northwest was conquered I saw 2 rebellions, and a 14 province big "India" formed in southwest India. The flag was the same colour scheme and a monarchy. They were fighting against India. Eventually, they won and south India was Monarchical India.

Again, around 70 turns later, when I was conquering Saudi Arabia, all of western Saudi became a communist Saudi Arabia with red and gold replacing the green and white on the flag. they got their independence and were a functioning nation.

Then, when I was playing as Parthia and conquered most of Russia and Scandinavia, I went to war with the Romans and lost rather quickly. As I was watching the Romans steamroll through Scandinavia and towards Russia and the middle east, Nations I once annexed declares independence and were at war with me. The nations had the same flag same governance and same leader.

From this, we can conclude that Civil wars happen when a nation's stability, happiness, and overall sovereignty are at stake.