Maria Kalergis (Maria Kalergis-Muchanow, née Maria Nesselrode; Warsaw, 7 August 1822 – 22 May 1874, Warsaw) was a countess, Polish pianist and patron of the arts.
At the age of seventeen Maria Nesselrode married Jan Kalergis, a rich landowner, who was much older and proved to be of a jealous disposition. Though they had a daughter, Marie, born in 1840 in Saint Petersburg, less than a year after their wedding they mutually decided to separate. Despite several attempts to overcome their aversion for each other, they would continue living separately, without divorcing, until Jan's death. He ensured Maria a prosperous life; to be sure, after their separation the division of their assets was in dispute, but they did allow her to tour Europe, including Saint Petersburg, Warsaw, Paris and Baden-Baden.
The course of Maria's marriage may have been influenced by her childhood experiences. A year after her birth, her father, Fryderyk Karol Nesselrode (of German descent) and his wife Tekla Nałęcz-Górska (of Polish descent), had separated due to personality differences. From her sixth year, Maria had been reared in Saint Petersburg in the home of her paternal uncle, Karl Robert Nesselrode, a Russian diplomat of German descent who for forty years (1816–56) was the Tsar's minister of foreign affairs and who saw to it that Maria received a thorough education.
She may have inherited her musical talent from her parents, and for a while took lessons from Chopin, who praised her talent. She was taught Polish by her mother and also spoke French (then the language of Polish salons), German, English, Italian and Russian.
She is remembered as the great love of Cyprian Norwid. For her, the acquaintance with the young poet was but one of many episodes in an active social life. He, shy and deferential, withdrew into the shade of the beautiful Maria's other admirers. For many years he harbored feelings for her that more than once served him as a source of poetic inspiration. He confided his feelings in letters to Maria Trembicka (General Stanisław Tręmbicki's daughter who later married a man named Faleński), a close friend of the "white siren." Encouraged by his confidante's friendship, he proposed to Maria Kalergis but was not accepted.