Kingdom of Portugal
After the Portuguese Restoration War of 1640–1668, the kingdom passed to the House of Braganza and thereafter to the House of Braganza-Saxe-Coburg and Gotha. From this time, the influence of Portugal declined, but it remained a major power due to its most valuable colony, Brazil. After the independence of Brazil, Portugal sought to establish itself in Africa, but was ultimately forced to yield to the British interests, leading to the collapse of the monarchy in the 5 October 1910 revolution and the establishment of the First Portuguese Republic.
United Kingdom of Portugal, Brazil and the Algarves
With the death of the Portuguese King John VI on 10 March 1826, his heir apparent, Brazilian Emperor Pedro I, inherited the Portuguese Crown, and reigned briefly as King Pedro IV. On 20 March 1826 the proclamation of the Brazilian Emperor's accession to the Portuguese Throne was made public by the Portuguese Council of Regency (that had been instituted by King John VI during his final illness, and that was led by the Infanta Isabel Maria, daughter of John VI and Pedro I & IV's sister). With this union of Crowns, the monarchies of Portugal and Brazil were once again briefly united, but there was no thought of a reunification of the two separate States. Accordingly, this brief union of Crowns in the person of Pedro I and IV remained always a personal union only, and not a real union or a rebirth of the United Kingdom.