That's not really accurate. The Centauri state IS a hereditary monarchy, it's just that one royal family died out and was replaced by a member of another noble house. That's actually pretty common. It's rather rare that one family will rule a country continuously throughout its entire history without being supplanted or replaced by another family for one reason or another. That's why the history of Egypt or the Byzantine Empire is broken up by the various dynasties (plural) that ruled it. Some only have one or two members in charge before they're replaced by another noble family. So having House Mollari take over for House Whatever doesn't change the Centauri from an imperial-style monarchy to some other form of government.Rocketboy1313 wrote: A Republic can also refer to any government run by a representative body, like the Roman Senate, the UK parliament, or the United States legislature.
Hereditary monarchs are not impossible in such a system, but I don't think the role of Emperor was strictly hereditary for the Centauri, otherwise Londo and Vir would have never been able to take the role....
The less restrictive the criteria are to serve and vote are the less "Republic" the government becomes and moves toward Representative Democracy, and then to limited Democracy, and then full democracy. The more restrictive the criteria become it moves toward (I forget this one, I think many would say Aristocracy), then Oligarchy, then Monarchy/Dictatorship...Keep in mind all of this is a spectrum.
I'm afraid your definition of a republic is a bit off. The existence of the British parliament in no way makes Britain, or its constituent parts, a republic. It's very name is the "United Kingdom." You can question the united bit, but the kingdom aspect is undeniable. Republic doesn't mean any state that's democratic. It's true there are democratic states with monarchs and democratic republics, but that doesn't make a parliamentary democracy equivalent to a republic.
These are the formal definitions you get when you google the terms:
Republic "a state in which supreme power is held by the people and their elected representatives, and which has an elected or nominated president rather than a monarch."
Monarchy "a form of government with a monarch at the head."
The definition of monarchy isn't altered by whether it's an Absolutist Monarchy where the king/queen rules unimpeded by law, or whether it's a titular figurehead acting as formal head-of-state while the real decisions are made by Parliament and a prime minister. A monarchy is still a monarchy by virtue of the fact that it has a hereditary head of a state, regardless of its democratic or non-democratic nature. Whether it's Saudi Arabia, Japan, Thailand, Morocco, Spain, Britain, the Netherlands, Brunei, Sweden--none of these countries refer to themselves as a republic, and for good reason. They're all kingdoms of one sort or another.
Likewise, a republic is a republic by virtue of the lack of a hereditary head of state. There are plenty of republics that are horrible dictatorships, but that doesn't transform them into monarchies. Pinochet's Chile was a thorough-going dictatorship, but he never claimed to be starting a dynasty, so it wasn't a monarchy. A dictatorial republic does not automatically transform itself into a monarchy. That can happen, but it isn't a guaranteed process.
Bashar Assad of Syria is the son of the last dictator, Hafez Assad, but Syria still calls itself a republic. Assad's rule is legitimized not by the fact that he is the scion of a hereditary ruling family (though in practice that's what it boils down to) but they claim that he is the 'elected' head of state. That is where he draws his formal 'legitimacy' from.
You can be a republic or a monarchy, but not both. It's a fundamental, counterposed definition. One rules the other out. Again, that says nothing about the democratic nature of the state. You can argue that the terms don't mean as much as they once did, or that the Kingdom of Britain has more in common with the French Republic than Britain does with the Kingdom of Morocco or France does with the People's Republic of Bangladesh. You can very well be right.
But the name of the state is important, it says something about what values the state nominally stands for and how it structures itself. The name can be a total lie and it frequently is. But that doesn't alter the fact that countries just don't willy-nilly adopt names for themselves. There's a reason why they do that and it'd be a mistake to overlook it--or to observe when the name doesn't match the reality.