In the ancient times, Portugal had been ruled by monarchy until the beginning of the twentieth century. A few decades after the establishment of the Portuguese republic a dictatorship was initiated by Antonio de Oliveira Salazar. However, after the Carnation Revolution heralded the coming of democracy in Portugal in the year 1974. The constitution of Portugal, formulated in 1976 defines it as a democratic republic. Similar to most of the countries which comprise the European Union, Portugal has no well defined or specific state religion, therefore declaring itself to be secular. The chief governmental devices which assure smooth running of the republic are the president of the republic, the assembly, the government and the legal courts of law. The president is the supreme authority while the assembly boasts of a unicameral parliamentary system. The prime minister is in charge of appointing the various officials and ministers of the nation and states. It is therefore the president and the prime minister who are responsible for efficiently looking after the interests of the people and at the same time providing their countrymen protection from external forces. There are two major political parties in Portugal followed by some minor parties as well. They are the Social Democratic Party and the Socialist Party. The others include CDS-PP, Bloco de Esquerda, Portuguese Communist Party.

All countries have certain defense mechanisms to curb internal strife and external invasions. Portuguese defense system comprises of the Air Force, Army and Navy. Time and again, Portugal has participated in maintaining the peace process in Bosnia, Kosovo, Afghanistan, Lebanon, East Timor and Iraq to ensure maintenance of peace amidst constant aggression.

Portugal joined the European Union in 1986 and has been the primary founder member of NATO. The Community of Portuguese Language Countries was also formed by the country in 1996.