History of Portugal: The first attempt at a Portuguese republican revolution breaks out in the northern city of Porto.

The Kingdom of Portugal under the House of Braganza was a constitutional monarchy from the end of the Liberal Civil War in 1834 to the Republican Revolution of 1910. The initial turmoil of coups d'état perpetrated by the victorious generals of the Civil War was followed by an unstable parliamentary system of governmental "rotation" marked by the growth of the Portuguese Republican Party. This was caused mainly by the inefficiency of the Portuguese monarchy as well as their lack of interest in governing the country and acceptance of the 1890 British Ultimatum, which forced the abandonment of the colonialist Pink Map attempt to unite the colonies of Angola and Mozambique.

Republicanism is a political ideology that encompasses a range of ideas from civic virtue, political participation, harms of corruption, positives of mixed constitution, rule of law, and others. Historically, it emphasizes the idea of self-governance and ranges from the rule of a representative minority or aristocracy to popular sovereignty. It has had different definitions and interpretations which vary significantly based on historical context and methodological approach. In countries ruled by a monarch or similar ruler such as the United Kingdom, republicanism is simply the wish to replace the hereditary monarchy by some form of elected republic.

Porto, also known in English as Oporto, is the second largest city in Portugal, after Lisbon. It is the capital of the Porto District and one of the Iberian Peninsula's major urban areas. Porto city proper, which is the entire municipality of Porto, is small compared to its metropolitan area, with an estimated population of just 252,687 people in a municipality with only 41.42 km² (16 sq mi). Porto's urban area has around 1.4 million people,(2025) in an area of 2,395 km² (925 sq mi), making it the second-largest urban area in Portugal. while the Porto metro area surpasses 1.8 million people. It is recognized as a global city with a Gamma + rating from the Globalization and World Cities Research Network.