I am Japan and I captured Nanjing. There were many rounds of unrest. During that unrest I eliminated the Chinese civilization. When I finally gained control of the city, it was completely within Spanish territory. When I gained control of the city, it was 92% Spanish. In a few rounds I am sure the city will revolt and eventually flip to Spain - but why? Before I took it, it was Chinese. It was a strong city, completely within China's borders. Why do the people of the city identify themselves as Spanish after only a few years? I have another city which I have controlled for THOUSANDS of years. It has 8.2 million citizens. 4% of them are 'Barbarian'. After 1000s of years, in the 21st century. So why aren't any of Nanjing's citizens Chinese? Because China no longer exists? Neither does a Barbarian civilization! There are no Barbarian cities and there haven't been for 1000s of years. Shenanigans! And why if I station 1 million troops there, doesn't the 92% Spanish nationality drop? Aren't those troops Japanese citizens? Shenanigans! I think I'll just turn off culture flipping next time. The concept is a bit silly anyway.