On March 10, 1784, Maria del Pilar Acedo y Sarria was born in Tolosa, Gipuzkoa, to José María Manuel Acedo y Atodo, Count of Echauz and Luisa de Sarria y Villafañe, Countess of Vado. Her father was a member of the renowned Royal Basque Society of Friends of the Country, an important eighteenth-century Enlightenment institution that fostered scientific, cultural, and economic learning with the aim of contributing to the improvement of Basque society. Raised in an Enlightened aristocratic environment, she spent most of her early years being educated in Vitoria-Gasteiz. In 1800 she married a nobleman, Ortuño María de Aguirre y del Corral, Marquis of Montehermoso, the head of the Provincial Council of Araba and also a member of the Royal Basque Society. They settled in a family palace in Vitoria-Gasteiz and would go on to have one daughter, Maria Amalia, in 1801. Domestic life, as befitted an aristocratic family so connected to the Royal Basque Society, was one of education, learning, debate, and numerous social gatherings. Maria del Pilar Acedo was fluent in several languages, wrote poetry, and played the guitar as well as being an enthusiastic participant in these gatherings with similarly Enlightened company.
In 1807, Vitoria-Gasteiz was occupied by French troops as part of the Peninsular War (1807-1814), Napoleon’s campaign to conquer the Iberian Peninsula. And in 1808, Napoleon named his older brother, Joseph Bonaparte, King of Spain. On a trip to Madrid that year, Acedo met the elder Bonaparte and he in turn visited Vitoria-Gasteiz, where he stayed at her palace. The two became lovers and she accompanied him when he returned to Madrid, where she “officially” became his mistress. At the same time, her husband was also welcomed in the king’s trusted circle. But his rule was not a happy one. He was unpopular and had no influence in the ongoing Peninsular War. He ultimately abdicated and returned to France after the French defeat at the Battle of Vitoria-Gasteiz in 1813. He was accompanied once more, by Acedo, whose husband had died (while accompanying King Joseph on a trip to France) in 1811. However, shortly after arriving in France, their relationship ended.
Having inherited lands, wealth, and titles from both her parents, Acedo was free to live indepedently in France. She lived temporarily in several places there, including Donibane Lohizune (Saint-Jean-de-Luz) in Lapurdi. In 1816, she remarried a French noble military officer Jacques Amádée de Carabène, and they settled in Carresse Castle in Bearn, where she lived off the income from her estates in Spain and spent the rest of her life carrying out charitable works. She lived a long and full life and died there in 1869.