She was like a dwarf, beady-eyed, hook-nosed, pock-marked and so ugly that even her portraits failed to flatter her. As well, she was precocious and had an extremely malevolent nature. Of Portugal's malicious Queens, she was probably the worst.
At the time of her marriage to the future King Joao VI, her uncle married Joao's sister and, when Carlota arrived in Portugal, it was said that Portugal had exchanged a whiting for a sardine. However, she had come from a happy court at Aranjuez to go to the gloomy Portugese one where her mother-in-law was already displaying signs of madness. Dom Joao, her husband, was good-natured, indolent, corpulent and almost as ugly as was she. His religious observances bored her and they were quite incompatible. Nevertheless they produced nine children and, because they were all handsome, it was rumoured that especially the younger ones had a different father. After the birth of the ninth child they began to live separate lives, he at Mafra and she at Queluz. Here it was rumoured that she had bought a retreat where she indulged in sexual orgies.
Then Napoleon ordered that Portugal should close its ports for England and that all British people should be arrested. Realizing that an invasion by Napoleon was imminent, the royal family decided to depart for their colony of Brazil. Carlota Joaquina wanted to join her mother in Madrid but, in November 1807, the mad Queen Maria I, Dom Joao, Carlota Joaquina, their children and practically the whole court amounting to some 16,000 to 18,000 people, embarked in an ill equipped fleet and set sail for Brazil.
Dom Joao and their sons sailed on one ship and Carlota Joaquina and their daughters on another. It was a long journey and everyone, the royal family included, became verminous and had to shave their heads. In March 1808 they arrived in Rio de Janeiro.
If her husband was happy in Brazil, Carlota Joaquina hated living there. Their eldest son lived with his father and Dom Miguel, the younger son, with his mother. Both sons were handsome and indulged in amorous adventures. Carlota Joaquina then tried to become Regent of the Spanish colonies in South America as well as heir to the Spanish throne but failed in both.

In February 1816 Brazil had been declared a Kingdom and a month later Queen Maria I died, and her son, Dom Joao, then became King of the United Kingdom of Portugal, Brazil and the Algarves. Joao VI would have been quite happy to remain in Brazil but, when peace was restored in Europe, he was forced to return to Portugal. Carlota Joaquina was delighted when they left with Dom Miguel and their daughters, and even the corpse of Queen Maria I, leaving Dom Pedro and his new bride, Archduchess Leopoldina, behind.
King Joao VI lived in the Palace of Bemposta and Queen Carlota Joaquina in Queluz. Though she lived there quietly, she became decidedly eccentric in dress and behaviour. However, their eldest son, Dom Pedro left behind as regent in Brazil, was proclaimed and crowned on 1 December 1822 as its independent Emperor. Joao VI refused to accept this until, in August 1825, he was persuaded by the British to do so. In March 1826, prematurely aged, he died. Claiming ill-health, Carlota Joaquina refused to attend his deathbed and started the rumour that her husband had been poisoned by the Freemasons.
Joao VI was described by Sir Marcus Cheke as: "He was charitable, intensely loyal to his friends, loyal to his country's allies, sentimental, easy-going, much attached to familiar faces and familiar
scenes. The defects of his character were mostly the excess of his good qualities. A less kindly man might have freed himself of his difficulties by a divorce, or by severity might have established
discipline among his sons."
The Emperor of Brazil now became King of Portugal as well; but knowing this to be impossible, Pedro abdicated in Portugal and made his eldest daughter Queen as well as betrothing her to Dom Miguel, his younger brother. In the meantime Infanta Isabel Maria, Carlota's daughter, was to be the regent in Portugal. About two years later the little queen set out, only to find upon arrival at Gibraltar that her uncle and fianc‚ had not only removed the regent but declared himself King of Portugal.
Carlota Joaquina was delighted with this turn of events but was not to see the outcome. Only fifty-five, she aged suddenly and became ill.She then lay for many weeks stretched on a mattress, ill-kempt, racked with pain and often delirious, until she died on 7 January 1830.
 

Source: Leo van de Pas