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
Although Pedro's abdication of the Portuguese Crown to Maria II was provided for even in the Constitution issued on 29 April 1826, the original deed of abdication, signed on 2 May 1826 contained conditions; however, those conditions were subsequently waived, as the abdication was later declared final, irrevocable, accomplished and fully effective by a decree issued by Pedro on 3 March 1828, just a few months before Infante Miguel's usurpation of the Throne and the start of the Portuguese Civil War (in accordance with a decree issued on 3 September 1827, Infante Miguel replaced Infanta Isabel Maria as Regent of Portugal on 26 February 1828, and he initially agreed to govern in the name of the Queen, but on 7 July 1828 he had himself proclaimed King with retroactive effect, assuming the title of Miguel I; Maria II would only be restored to the Throne in 1834, at the conclusion of the Civil War). In any event, Pedro's unconditional confirmation of his abdication reinforced the impossibility of a new union between Portugal and Brazil.