The GNR was formed in 1913 as a heavily armed paramilitary constabulary organized up to battalion strength. It was intended as a check against the military and was first employed to confront monarchist-inspired revolts within the ranks of the armed forces. Although its essential mission was one of maintaining order in the countryside, the GNR's activities were subsequently extended to those of helping the urban police to control demonstrations and quell labor unrest.

In 1990 the GNR numbered approximately 19,000 officers and men. It was equipped with Commando armored cars and twelve Alouette II helicopters transferred from the German army. The guard was organized into battalions stationed in the major cities and companies and sections in district capitals and smaller communities. Highway patrols were conducted by a separate Traffic Brigade and by rural units of the GNR.

Reserve and career officers from all branches of the armed forces could be seconded to tours of duty in the GNR on a voluntary basis. Reservists who were university graduates could apply to continue as GNR officers upon completion of their military obligations.

Data as of January 1993

NOTE: The information regarding Portugal on this page is re-published from The Library of Congress Country Studies and the CIA World Factbook. No claims are made regarding the accuracy of Portugal National Republican Guard information contained here. All suggestions for corrections of any errors about Portugal National Republican Guard should be addressed to the Library of Congress and the CIA.