Beaver Island

It's turn 300 when I suddenly realize that one of the cities on the map is not inhabited by the Mayans, the Englishmen or even the Babylonians, but by barbarians! This was not possible in Civilization III. The city, called Circassian, is on an island north from my main continent. The island also contains a lot of beavers which are a good source of furs. I shall call that island the Beaver Island from now on.
Naturally it's clear that the city cannot continue under a Barbarian reign so I immediately begin shipping my riflemen out to the Beaver Island. I conquer the city after just eight turns. In the process one of my rifleman units gets killed against Barbarians with longbows but other than that it's a flawless victory.

Somewhere along the way Hammurabi contacts me and we negotiate a deal: they give me 150 gold and the knowledge of Nationalism and I give them Replaceable Parts. The former technology enables the Nationhood civic and the latter one leads to Rifling and also allows building lumber mills. I then change my legal civic from Vassalage to Nationhood, mostly because it is cheaper and I have some budget issues. I have already begun building courthouses to cut the maintenance costs of my cities as well as groceries and markets to increase commerce.