Estado Novo (Portugal)
King Carlos I of Portugal confirmed colonial treaties of the 19th century that stabilized the situation in Portuguese Africa. These agreements were, however, unpopular in Portugal, where they were seen as being to the disadvantage of the country. In addition, Portugal was declared bankrupt twice—first on 14 June 1892 and again on 10 May 1902—causing industrial disturbances, socialist and republican antagonism, and press criticism of the monarchy. Carlos responded by appointing João Franco as Prime Minister and subsequently accepting Parliament's dissolution. In 1908, Carlos I was assassinated in Lisbon. The Portuguese monarchy lasted until 1910 when, through the 5 October revolution, it was overthrown and Portugal was proclaimed a republic. The overthrow of the Portuguese monarchy in 1910 led to a 16-year struggle to sustain parliamentary democracy under republicanism – the Portuguese First Republic (1910–1926).
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.