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.
Manuel II of Portugal
Since both the Dover and Paris Pacts did not resolve the issue of succession and there are no known documents proving them, there was no direct heir to the defunct throne. Manuel also made it clear that the branches of the Portuguese royal family (including the Imperial family of Brazil, the Braganza-Orleans, and the descendants of the Duke of Loulé) ended with the last direct male heir to the House of Braganza. Still, the monarchist Integralismo Lusitano movement acclaimed Duarte Nuno, Duke of Braganza as King of Portugal, since Miguel I of Portugal, on the death of his grandchild, was head of the Portuguese Royal Family. Their justification, ironically, included the fact that both branches had met to determine the line of succession in Dover and Paris, even though those accords were both later repudiated.