'''Harmonia''', formally ''The State of Harmonia'', (or ''Civitas Harmoniae'') is a sovereign federal polity on Equus, founded in 3336 AE. As of the 37th century, it is the largest state on Equus by territory, economic output, and population. Although sovereignty is vested in the ''Civitas Harmoniae'' and not in its constituent territories, these territories are not mere administrative districts and enjoy considerable autonomy under its federal system. 

Harmonia's head of state is a non-partisan [[President of Harmonia|President]], who is selected with a direct popular election. The president is the chief executive and represents the state in foreign relations. The head of government is the Prime Minister of Harmonia, who is elected by the state's unicameral legislature, the Senate. The 252 Senators mostly represent electoral districts defined by a non-partisan expert panel. Formerly, there were a significant (20-30%) number of at-large senators selected by means other than a democratic election in an electoral district, but the Senate Reform Act of 3402 reduced their numbers greatly, eliminating all senate seats reserved for the appointees of feudal nobility, the largest category of such senators. The remaining senators who are not directly elected are the Procurators of the various [[Curacies]] of Harmonia, who are entitled to a vote and a seat in the senate and have the further right to vote by proxy, unlike other senators. However, as part of the compromises around the Reform Act of 3402, they have agreed as a bloc to abstain from voting, except in cases of 'dire emergency.' Harmonia has an independent judiciary, of which the Harmonic Court of Final Appeal is the court of last resort.

Harmonia has both directly controlled regions, and special administrative regions, which have more autonomy. Most SARs have come about from the peaceful accession of formerly-sovereign states to Harmonia. Territory that was uninhabited (due to crystal forest) and annexed territories lacking any effective government previously were usually incorporated directly.

A somewhat unique feature of the state is the system of ''[[curacies]]'', derived from the traditional administrative districts of magical law that existed under pre-catastrophic governments. The curacies are technically sovereign (compare the Sovereign Military Order of Malta or the Vatican City-State for Earth examples) and enjoy extraterritoriality from Harmonia and its federated jurisdictions. Some curacies even exist outside of Harmonia.  Each curacy is technically independent of the others, but in a personal union. (The [[Curatrix]] is their sovereign; she appoints procurators to represent her in each curacy.) However, the curial courts are subject to the appellate jurisdiction of the Harmonic Court of Final Appeal, and some appointments of high officials in the curacies require confirmation by organs of the State of Harmonia. 

SARs within Harmonia have broad legislative and policy independence, provided that rights of the citizens are respected (including freedoms of speech, movement, association, religion, freedom from unreasonable searches or seizures, equality before the law, and various other civil rights) and contributions to the common defence and institutions, commensurate to the resources of the SAR, are made.