Monarchy and City-state
After the starting moment of a scenario, the leader ages and then has children, which can be historical, or not. If historical, it could be taken from the wikipedia, if not — from a bank of specific nation's names, which fit in.
Apart from that, throne could be inherited based on the primogeniture (or else) law. So that the monarch has a pool of kids, from which, using an algorithm, a future leader is chosen. Player can also host a coup, establishing a tyrant or someone else as the monarch, and... it may possibly be a leader of another country, although, in t