I'm working on a setting with the main nation being a republic, but it has medieval knights. Are knights necessarily a product of feudalism or monarchies? What about medieval republics like Venice? Did it have knights? One possible explanation I'm considering is that the nation was once a feudal monarchy, but it was overthrown and replaced with a republic. The knights are what is left over from the old system and may have even led the coup. I figured they would play a prominent role in politics either under the service of the new government, or running the governments themselves either directly, or influencing the government officials. Maybe they found an order dedicated to justice and peace where they try to maintain order, enforce the law, and protect the weak.