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).
Portuguese Empire
When King Philip II of Spain (Philip I of Portugal) inherited the Portuguese crown in 1580 there began a 60-year union between Spain and Portugal known to subsequent historiography as the Iberian Union. The realms continued to have separate administrations. As the King of Spain was also King of Portugal, Portuguese colonies became the subject of attacks by three rival European powers hostile to Spain: the Dutch Republic, England, and France. With its smaller population, Portugal found itself unable to effectively defend its overstretched network of trading posts, and the empire began a long and gradual decline. Eventually, Brazil became the most valuable colony of the second era of empire (1663–1825), until, as part of the wave of independence movements that swept the Americas during the early 19th century, it broke away in 1822.