The Portuguese First Republic spans a complex 16 year period in the history of Portugal, between the end of the period of constitutional monarchy marked by the 5 October 1910 revolution and the 28 May coup d'etat of 1926.

The inner part of the coin shows in the centre the Portuguese coat of arms and the Republica effigy, two of the most representative symbols of the Portuguese Republic. The Portuguese Efigie da Republica is represented as a young woman wearing the phrygian cap, modeled after the Liberty of Eugene Delacroix' Liberty Leading the People. As a national distinction, the Portuguese Republic is represented wearing green and red clothes.