Portugal's government and administrative structure has changed many times in the past 100 years, since the New Republic was formed. Here is a brief summary to help you to understand the systems and the difficulties. 

President and Assembly

The President of the Republic of Portugal is the head of state and is elected every 5 years.

The Assembly of the Republic (Assembleia da República) is the Portuguese parliament. It is located in a historical building in Lisbon, referred to as Palácio de São Bento, the site of an old Benedictine monastery. The Palace of São Bento was formerly known as the seat of the National Assembly (Assembleia Nacional) during the Estado Novo regime.

The Assembly is made up of between 180-230 elected members. Members are decided bases on Proportional Representation system of election, and elections are held every 4 years.

The President of the Assembly is usually nominated by the majority party, and the Prime Minister is appointed by the President of teh Republic.

Administrative Divisions

Between 1926 and 1974 the administration of Portugal was very centralised and was divided into 20 Districts, 18 on Mainland Portugal plus the Azores and Madeira. This district system dates back to 1835 and it still the bases of electoral division, football associations and more.

The current government structure is based on the 1976 Constitution, adopted after the 1975 Carnation Revolution. It allows a high degree of freedom for the lower tiers of government; civil parishes (freguesias), municipalities (municípios or concelhos) and administrative regions (regiões administrativas) to decide their own expenditures.

A referendum was conducted in 1998 in order to implement an change to 8 mainland statutory and political regions with some degree of autonomy and to abolish districts, but it was rejected.

The "district" has been removed from the legal framework, but still remains an important and relevant division and it is still recognized by the general public.

In addition, in May 2003 a new law allowed the municipalities to organize themselves into inter-municipal communities (comunidades intermunicipais), that can be of general or specific purposes; and metropolitan areas (áreas metropolitanas), that can be of two types: great metropolitan areas (grandes áreas metropolitanas) of which there are 7, and urban communities (comunidades urbanas), there are 12 of these.

The 2011 bailout accord requires the reduction of the number of municipal and parish local governments after July 2012, we are now waiting for these changes to be announced, but you can expect they will take a long time to implement in a country that does not adopt changes very well.

Portugal was redefined during European integration, for statistical purposes. The name used for this is NUTS (Nomenclature of Territorial Units for Statistics) there are 3 regional levels (I, II, III) for this purpose. Although the NUTS regions are used by the Portuguese government, they do not have a legal status in law but are used throughout the EU for statistical purposes.