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
Portugal as a country was established during the Christian "Reconquista" against the Moors who had invaded the Iberian Peninsula in 711 AD. Despite attempts at independence since its foundation as a county in 868, only after the Battle of São Mamede in 1128, where Portuguese forces led by Afonso Henriques defeated forces led by his mother, Teresa, the County of Portugal affirmed its sovereignty and Afonso styled himself Prince of Portugal. He would later be proclaimed King of Portugal at the Battle of Ourique in 1139 and was recognised as such, by neighbouring kingdoms, on the Treaty of Zamora, in 1143.