Commonly known by her nickname, Alcipe, the Marquise was a prime figure in the Portuguese Neoclassic a proto-Romantic literary scene, while still a follower of Neoclassicism when it came to painting.

Her early success as a poet at the convent started her lifelong career which would lead her to becoming one of Europe's most noteworthy literary figures at the time.

The convent was often a location of retreat to the members of the Arcadia, a literary society, and to distinguished poets like Francisco Manuel do Nascimento, best known by his pen-name, Filinto Elísio.

Leonor finally left the convent in 1777, when she was twenty-seven years old, at the orders of the newly acclaimed Queen Maria I, who sought to reverse all the policies and actions of the Marquis of Pombal, whom she despised.

Leonor rapidly became a personality of the aristocracy, her intelligence and charm having captivated the nobles who expected a girl ruined by a forced convent life.

Her prime suitor was Carlos Pedro Maria José Augusto, Count of Oyenhausen-Grevenburg, a nobleman and military-man from the Holy Roman Empire.

In 1762, Carlos Pedro came to Portugal with his cousin, William, Count of Schaumburg-Lippe, who was invited by the Marquis of Pombal to train the Portuguese army.

Present were Queen Maria I and King Pedro III, Leonor's godparents, alongside many of the most important nobles at the Portuguese Royal Court.

In 1779, Count Carlos Pedro moved the couple to Porto, as he was made commander of the VI Royal Infantry Regiment, which was based in that city.

His post in Porto would only be temporary, for in 1780, Queen Maria I appointed Count Carlos Pedro as her minister plenipotentiary to the Imperial Court of Vienna and the couple moved thereafter.

When Pope Pius VI visited the Imperial Viennese Court, he received a private audience with Leonor, where she was decorated by the Supreme Pontiff.

Being a high-ranking official of the Portuguese Royal Court, Leonor became a popular personality very quickly and she opened a literary salon, one of the most exclusive and notable in the kingdom.

Grief-stricken, Leonor took her family to London, where she stayed in the palace of Domingos de Sousa Coutinho, Count of Funchal, the Portuguese ambassador to the United Kingdom.

She stayed there until 1814,[3] the year after her brother, Pedro de Almeida Portugal, 3rd Marquis of Alorna, died without any living descendants and Leonor became the rightful heir to the title.

In 1822, Leonor's only son, João Carlos Ulrico de Almeida e Oyenhausen, Count of Oyenhausen-Groewenbourg, died while serving as the Lieutenant-Colonel of the IV Royal Cavalry.

As a prominent member of the Portuguese High Nobility, Leonor would customarily have attended the marriage of Queen Maria II to Ferdinand of Saxe-Goburg and Gotha,[1] but she was unable to, due to her advanced age.