Irombrozia/Republic of Fwuvoghor. Me and Ban TRIED to do this, and there was (some) limited success to it in RoF, and even more limited success in Irombrozia.
But, hereditary monarchies would be neat. The issue is an OOC one, however. If the same player is playing all those characters... it's boring for everyone else. Which is why you need multiple players, and marriages, where the same player does not continually get the "heir." You get a "royal family" which includes characters played by five or six players after a few generations.
Kelley (House Kindon) and I are trying to do a variant of this, with other nobles taking Ruler positions in the interim while the kids grow up to prevent the OOC stranglehold problem. We'll see how well it works out.
