With the continuous presence of the Court in Rio de Janeiro, most Portuguese military garrisons in Brazil chose to side with the King over the Cortes without bloodshed, with some exceptions, like the Montevideo garrison, were General Lecor had to seize Álvaro da Costa and take control of the city in a local coup. While some native Brazilian agitation existed, the crisis didn’t develop into a Brazilian versus Portuguese scenario outright, but in a Portuguese absolutist and Brazilian vs Portuguese constitutionalist one.
In Portugal, the metropole suffered due to the absence of the country’s monetary reserves, which had been transported to Rio de Janeiro in 1808. Worse, the best part of the fleet, as well as all colonial possessions, also chose to obey the power of the King rather than the writ of the Cortes. To achieve a little bit of legitimacy, the Liberal government coerced the King’s older sister, Isabel Maria, to take the post of Regent for her nephew, the son of the King and Queen Leopoldina, while he was still in Rio de Janeiro, now recognized by it as the legitimate ruler of the Portuguese Empire, as his father had legally forfeited his rights after his act of treason against the body.
Nonetheless, after mustering the Divisão Auxiliadora in Rio de Janeiro, together with pieces of other Portuguese military garrisons as well as Brazilian volunteers from over all Brazil, the King managed to create a well-equipped force of roughly five thousand men, the “Exército da Reconquista”, which was supposed to take Portugal back from the heathens like the Crusaders of old did.
But when the mighty fleet of the King stopped to resupply in the loyalist Azores, they were confronted by a frenetic surprise attack from the liberal armada. In special, a British Mercenary named Thomas Cochrane, made captain of a ship of the line in the constitutional fleet, managed to sink and capture many loyalist ships.
While the bulk of the King’s Armada managed to sail back to Rio de Janeiro, confidence in an easy victory was tarnished, and the Constitutional side managed to achieve control of the Azores, Madeira and Cabo Verde. The war then turned into a sluggish conflict of maritime raids and skirmishes along the Atlantic, either side refusing to engage in a decisive battle.
To solve this, and under the secret instructions of her older brother, Isabel Maria, the nominal head of the constitutionalist side, sent secret letters to King Louis XVIII of France, asking for French intervention to stop the tide of Jacobinism in Portugal and to turn it back to it’s rightful King by the Grace of God. But before Paris could answer with force, her conspiracy was discovered by the de facto leaders of the liberal government in Lisbon, which tried to seize her to no avail while she escaped to Madrid, where the other sister of King Miguel, Maria Isabel, was married to King Ferdinand VII of Spain.
As a retaliation for the Infanta’s conspiracy, the Lisbon government started a reign of terror against those who had Loyalist sympathies, and in a moment of foolishness, a Portuguese Republic was declared, to the anguish of great powers of the Congress of Vienna, who dreaded the return of the revolutionary fervour.
Spain itself had suffered it’s own liberal constitutional revolution in 1820, when the Tenente-Coronel Rafael de Riego, which was supposed to lead the reconquest of Spanish America, turned his guns to Madrid, taking the homeland and putting Spain under a constitutional monarchy with King Ferdinand VII, a difficult cohabitation.
But when the Portuguese Republic was declared in 1823, both the King of Spain and the leader of the Spanish Cortes smelled an opportunity to fulfil an old Spanish aspiration, to take the Portuguese throne for itself, a much closer endeavour than the lengthy reconquest of the Spanish America.
Mustering an army before the other great powers could react, Madrid invaded Portugal, with the help of the more moderate Portuguese liberals, taking Lisbon and placing Queen Maria Isabel of Spain, a Braganza by birth, as the Queen of Portugal under a Constitutional monarchy. While the prospects of a Queen de facto controlled by the Spanish Crown were not good in the books of any faction in Lisbon, it was considered to be preferable to the inevitable white terror that would come should King Miguel managed to retake the old homeland.
At the same time, the elevation of his wife to the throne of Portugal endeared King Ferdinand VII of Spain with his own liberal government, preventing Paris from intervening in the Iberian Peninsula now that the worst excesses of the liberal movements were controlled by it’s own moderate counterparts.
The war between Lisbon and Rio de Janeiro entered into a new phase of constitutional supremacy, with the covert help of the Spanish Navy, hoping to use Brazil as a springboard to retake other Spanish possessions in South America. In 1824, a small fleet commanded by Thomas Cochrane managed to take Luanda by surprise, sacking the African city with extreme brutality and taking it’s riches as payment.
Rio de Janeiro, while initially in the advantage, was now becoming increasingly outclassed by the constitutional navy, specially now that Madrid’s support was turning the tide of the war decisively. With the loss of Luanda, as well as the rest of Angola, the easy connection between Rio and it’s African and Asian colonies was lost.
While another Constitutional Fleet was already sailing towards Mozambique, the British started to pressure the two governments, Lisbon and Rio, to stop hostilities and to sign a treaty, fearful that the continuation of the war would see Portuguese America reconquered with Spanish help.
In London, representatives of the two sides tried to negotiate a peace, but neither side would concede on the most important matter: who should sit on the Portuguese throne. At the end of the negotiation, it was merely established that hostilities would cease and commerce would be re-established between European and American Portugal. The Asiatic Portuguese possessions were supposed to be kept under the power of Rio de Janeiro, but the taking of Mozambique by Lisbon made this proposition null and void, as Macau and East Timor quickly accepted the authority of the Cortes to allow their continuous access to the European market, while the British took Goa by force and placed it under it’s “temporary tutelage”.
The Portuguese Empire was effectively partitioned between two Portuguese monarchs, King Miguel I in Rio de Janeiro, ruling over all of Brazil, as well as his older sister Maria Isabel, ruling as a constitutional monarch in Lisbon under the auspices of her husband and the Cortes, controlling the remaining Portuguese Empire. Both monarchs would go to their graves claiming the whole Empire as theirs.
While this was never intended by King Miguel, this is considered by historians as the moment when Brazil de facto achieved it's liberty from the metropole, even if in a convoluted way, in one of the most counterintuitive liberation process of all American history.
One could say that Brazil lost the war, but won it's independence, and Portugal won the war, but lost it's empire.