Political organization of the autonomous communities

The basic institutional law of the autonomous community is the Statute of Autonomy. The Statutes of Autonomy establish the denomination of the community according to its historical identity, the limits of their territories, the name and organization of the institutions of government and the rights they enjoy according the constitution.

The government of all autonomous communities must be based on a division of powers comprising:

a Legislative Assembly whose members must be elected by universal suffrage according to the system of proportional representation and in which all areas that integrate the territory are fairly represented;
a Government Council, with executive and administrative functions headed by a president, elected by the Legislative Assembly and nominated by the King of Spain;
a Supreme Court of Justice, under the Supreme Court of the State, which head the judicial organization within the autonomous community.
Besides Andalusia, Catalonia, the Basque Country and Galicia, which identified themselves as nationalities, other communities have also taken that denomination in accordance to their historical regional identity, such as the Valencian Community, the Canary Islands, the Balearic Islands, and Aragon.

The autonomous communities have wide legislative and executive autonomy, with their own parliaments and regional governments. The distribution of powers may be different for every community, as laid out in their Statutes of Autonomy. There used to be a clear de facto distinction between so called "historic" communities (Basque Country, Catalonia, Galicia, Andalusia) and the rest. The "historic" ones initially received more functions, including the ability of the regional presidents to choose the timing of the regional elections (as long as they happen no more than four years apart). As another example, the Basque Country, Navarre and Catalonia have full-range police forces of their own: Ertzaintza in the Basque Country, Policía Foral in Navarre and Mossos d'Esquadra in Catalonia. Other communities have a more limited force or none at all (like the Policía Autónoma Andaluza in Andalusia or the BESCAM in Madrid). However, the recent amendments made to their respective Statute of Autonomy by a series of "ordinary" Autonomous Communities such as the Valencian Community or Aragon have quite dilluted this original de facto distinction.

[edit] Subdivisions
Autonomous communities are composed of provinces (provincias), which serve as the territorial building blocks for the former. In turn, provinces are composed of municipalities (municipios). The existence of these two subdivisions is granted and protected by the constitution, not necessarily by the Statutes of Autonomy themselves. Municipalities are granted autonomy to manage their internal affairs, and provinces are the territorial divisions designed to carry out the activities of the State.

The current fifty province structure is based-with minor changes-on the one created in 1833 by Javier de Burgos. The communities of Asturias, Cantabria, La Rioja, the Balearic Islands, Madrid, Murcia and Navarre, having been granted autonomy as single-provinces for historical reasons, are counted as provinces as well.