Maria was the eldest daughter of King Dom José I (Joseph I) of Portugal and Queen Mariana Victoria.

Upon ascending the throne, Maria dismissed her father's powerful chief minister, Sebastião José de Carvalho e Melo, 1st Marquis of Pombal.

Her father José was the eldest surviving son of the reigning King Dom João V (John V) of Portugal.

Her mother, Mariana Victoria, was the eldest daughter of King Don Felipe V (Philip V) of Spain.

As José's eldest child, Maria became his heir presumptive and was given the traditional titles of Princess of Brazil and Duchess of Braganza.

[2] After the earthquake, King José was often uncomfortable at the thought of staying in enclosed spaces, and later experienced claustrophobia.

[3] However, the queen suffering from melancholia and declining mental health (perhaps due to porphyria) made her incapable of handling state affairs after 1792.

During her reign, the trial, conviction and execution of ensign Joaquim José da Silva Xavier, known as Tiradentes, took place in 1789.

The queen's confessor, Inácio de São Caetano, Titular Archbishop of Salonica, died almost four weeks later.

[6] In February 1792, Maria was deemed insane and was treated by Francis Willis, the same physician who attended the British king George III.

[4] When the Real Barraca de Ajuda burnt down in 1794, the court was forced to move to Queluz, where the ill queen would lie in her apartments all day.

[citation needed] In 1801 Spanish Prime Minister Manuel de Godoy sent an army to invade Portugal with backing from the French leader Napoleon, resulting in the War of the Oranges.

Though the Spanish ended their invasion, the Treaty of Badajoz on 6 June 1801 forced Portugal to cede Olivença and other border towns to Spain.

On 29 September 1801 Prince Dom João signed the Treaty of Madrid (1801), ceding half of Portuguese Guyana to France, which became French Guiana.

[5] The refusal of the Portuguese government to join the French-sponsored Continental Blockade against Britain culminated in the late 1807 Franco-Spanish invasion of Portugal led by General Jean-Andoche Junot.

Under pressure by local aristocracy and the British, the prince regent signed a commercial regulation after his arrival that opened commerce between Brazil and friendly nations, which in this case represented the interests of Great Britain above all.

This law broke an important colonial pact that had previously allowed Brazil to maintain direct commercial relations only with Portugal.

Portuguese forces under British command distinguished themselves in the defence of the Lines of Torres Vedras (1809–1810) and in the subsequent invasion of Spain and France.

Maria is a greatly admired figure in both Brazil and Portugal due to the tremendous changes and events that took place during her reign.

A large marble statue of the queen was erected at the Portuguese National Library in Lisbon by the students of Joaquim Machado de Castro.