History of Portugal (1834–1910)
Militant Republicans and their allies in the Carbonária were not willing to remain in the shadows of the constitutional monarchy. Between 4–5 October 1910, members of the Carbonária, republican youth, and elements of the army instigated a coup d'état against the already weak constitutional monarchy. The young king and his family, after a few miscues, escaped from the Palace in Mafra to exile in England. On the morning of 5 October 1910, the Republic was declared from the balcony of Lisbon City Hall, ending eight centuries of monarchy in Portugal.
Portugal–Spain relations
In 1974 the dictatorship of the "Estado Novo" was brought to an end by a military "coup" known as the Carnation Revolution. This left Spain increasingly isolated from the rest of Europe, which lasted until the death of Franco a year later, after which Spain returned to being a constitutional monarchy and embraced parliamentarism. The PREC that had followed the Carnation Revolution in Portugal came to an end in 1976 and Portugal also became a democracy.