The Republic of Elpida, was a nation that existed from 20,167 CE to 22,331 CE, existing for 2164 years before it was replaced by a reformed Republic to include Elpida and Its Colonies in Equal conditions, renaming itself Republic of Anthropos. Then this nation would in turn be replaced after the Second Civil War events to give rise to the current Empire of Mankind.
The Republic was created when Anarian Settlers left the Confederacy of Borealis after the Anarian Fever Incidents on planet Anar in search of a new home away from the rule of the Confederacy. They settled in Planet Elpida, on the Lewis Galaxy. The start was hard for the first settlers, and they organized themselves on a Republican Fashion, with high democratic values and rule in an indirect democratic way, with parties representing several interests in which people could vote to.
The Republic was effective because since the early days, helped the entire population of Elpida to come together as one nation, preventing secession into several smaller countries.
The Republic was isolated and had to function mostly as an autarky, with little comercial contacts with the outside universe. This led the first colonist to study deeply their now home planet, remember where they came from and a strong nationalist sentiment grew among settlers, what helped them expand into nearby worlds.
The Republic was no longer just revolving around Elpida, and when the Colonies started to flourish and become fully populated and functional worlds on their own, the Republic had to be reformed to include treatment of this worlds in a more egalitarian way, similar to Elpida. Although Elpida remained the Capital, Mitra and Pax hold some important institutions, that would later become the Imperial Supreme Court and the Legislative Parliament of the Empire,making them Capitals, alongside Elpida.