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.
United Kingdom of Portugal, Brazil and the Algarves
By a provision of the Letters Patent of 13 May 1825, confirmed by the Treaty on the Recognition of Independence in spite of the secession of Brazil from the Portuguese Monarchy, the Portuguese King, John VI, was allowed to use for the remainder of his life the honorary title of "Emperor of Brazil", with the caveat that this title was honorary and ceremonial only, and that Pedro I and his successors in the independent Brazilian Crown were the only actual Emperors of Brazil. This honorary title ceased to have effect upon the demise of King John VI on 10 March 1826.