See biography by G. C. Williamson (1897).
Cosway's family suffered a tragedy during her childhood when a mentally ill nursemaid murdered four of Cosway's brothers and sisters. The nurse was caught after she was overheard speaking about planning to murder Maria. The nurse thought that her young victims would be sent to heaven after she killed them and was sentenced to life in prison. Only Maria, her brother Richard and a younger sister, Charlotte survived.
On her father's death Maria expressed a strong desire to become a nun; her mother, however, brought her to England three years after her husband's death. The family moved to London in 1779.
While still in Florence, Cosway studied art under Violante Cerroti and Johann Zoffany. From 1773 to 1778, she copied Old Masters at the Uffizi Gallery. For her work, she was elected to the Academia del Disegno in Florence in 1778. She also went to Rome, where she studied art under Batoni. She received further tuition from Mengs, Fuseli, and Joseph Wright of Derby.
Two female artists, Angelica Kauffmann and Mary Moser, were among the original members of the Royal Academy of Arts in London in 1768. Kauffmann helped Cosway to participate in academy exhibitions. In 1781 she exhibited for the first time at the Academy the following three works: "Rinaldo", "Creusa appearing to Aeneas" (engraved in mezzotint by V. Green), and "Like patience on a monument smiling at grief". She went on to gain success as a painter of mythological scenes.
Cosway's Italian manners were so foreign that her husband kept her secluded until she fully mastered the English language. However, Richard realized his wife's talent and helped her to develop it. More than 30 of her works were displayed at the Royal Academy of Art from 1781 until 1801. She soon increased her reputation as an artist, especially when the portrait of the Duchess of Devonshire in the character of Cynthia was exhibited. Among her personal acquaintances were Lady Lyttelton, the Hon. Mrs. Darner, the Countess of Aylesbury, Lady Cecilia Johnston, and the Marchioness of Townshend.
In 1784, the Cosways moved into Schomberg House, Pall Mall, which became a fashionable salon for London society. Richard was Principal Painter of the Prince of Wales and Cosway served as hostess to artists, members of royalty including the Prince, and politicians including Horace Walpole, Gouverneur Morris and James Boswell. She could speak several languages, and due to her travels in Italy and France, she gained an international circle of friends. She was friends with the fashionable elite such as Angelica Schuyler Church and artist John Trumbull, and it was at this time that she met Thomas Jefferson. Known as "The Goddess of Pall-Mall", she was also an accomplished musician who would organize concerts and recitals for her guests.
Richard and Maria had one child together, Louisa Paolina Angelica, but the couple eventually separated. It is not known whether Maria left her husband, or whether they had an open marriage, but she often travelled on the continent, on one occasion accompanied by Luigi Marchesi, a famous Italian castrato, whose portrait Richard Cosway painted, and was afterwards engraved by Luigi Schiavonetti (1790). At the same time Richard was having an open affair with Mary Moser, with whom he travelled for six months. In his notebooks he made "lascivious statements" and "invidious comparisons between her and Mrs Cosway", implying that she was much more sexually responsive than his wife.
When staying in Lyons she made a pilgrimage to the shrine of the Virgin Mary at Loreto, fulfilling a vow she had made to do so after giving birth to a living child. However, her daughter died while she was on the continent.
Cosway also showed an interest in French politics. In 1797, then living on Oxford Street in London, she commissioned artist Francesco Cossia to create what was to be the first portrait of Napoleon ever seen in England. Cosway may thus have been the first person in Britain to see the face of Napoleon. Her commission of the portrait would later be called the "earliest recorded evidence of British admiration for Napoleon." The painting was later acquired by Sir John Soane and is now on display in the Breakfast Room of Sir John Soane's Museum.
While living in Paris between 1801 to 1803 Cosway engaged on a project to copy the paintings of the Old Masters from the Louvre for publication as etchings in England, and while copying Napoleon Crossing the Alps by her friend David, she met Napoleon. She was close friends with Napoleon's uncle, Cardinal Joseph Fesch, and would later give British visitors tours of the Cardinal's art collection during the Peace of Amiens. One historian pointed out that her admiration for Napoleon may have been inspired by her then lover Pasquale Paoli, a Corsican general in exile in London who had been an associate of Bonaparte's.
Her Louvre project was considered her most amitious undertaking, but it remained unfinished after the death of her daughter.
Cosway and Jefferson shared an interest in art and architecture and attended exhibits throughout the city and countryside together. He would write of their adventures: "How beautiful was every object! the Pont du Neuilly, the hills along the Seine, the rainbows of the Machine of Marly, the terraces of Saint Germain, the chateaux, the gardens, the statues of Marly, the Pavilion of Louveciennes... In the evening, when one took a retrospect of the day, what a mass of happiness had we travelled over!" Over the course of the six weeks, Jefferson developed a romantic attachment to Cosway as they spent each day together.
Upon her departure for London at the insistence of her husband, he wrote Cosway a love letter dated October 12-13, 1786 that has been called "The Dialogue of the Head vs. the Heart", in which he writes of his head conversing with his heart and the struggle between the practical and the romantic. He wrote the letter with his left hand because he had broken his right wrist during Cosway's visit, while jumping over a fountain in a rush to meet her.
Scholars suggest that Jefferson was particularly partial to a romantic attachment at this point in his life, because his wife had died four years earlier, he had just learned of the death of his daughter Lucy, and his other children were away at school. Cosway, by at least one account, began to develop stronger feelings for Jefferson and traveled to Paris to meet him again, only to find him more distant this time. Because Cosway was a devout Catholic who did not want to have children and compulsively worried about pregnancy, according to some historians nothing further came of their affair besides correspondence. Their letters would continue the rest of Jefferson's life after she contacted him, following Jefferson's ending of the letters while he was still in Paris. Historians assert that the relationship was romantic mostly on Jefferson's side, and Cosway was his opposite, more artistic than rational. In any case, both parties saved their letters to each other.
Before Jefferson left Paris, he wrote to her, "I am going to America and you are going to Italy. One of us is going the wrong way, for the way will ever be wrong that leads us further apart."
Cosway also introduced Jefferson to her friend Angelica Schuyler Church, the sister-in-law of his rival Alexander Hamilton, who kept up a correspondence with both Jefferson and Cosway in later life; Church's correspondence with both is now preserved at the University of Virginia's archive.
He would keep an engraving done by Luigi Schiavonetti, from a drawing Richard made of Maria, in Monticello. Cosway had Trumbull create a portrait of Jefferson which she kept. The portrait was later given as a gift from the Italian government to the American government on the occasion of America's bicentennial in 1976 and now hangs in the White House.
A letter survives at the University of Virginia in which Cosway mourns the loss her old friends following the death of Angelica Schuyler Church. As a tribute to Church, Cosway designed a temple ceiling depicting the Three Graces surrounding her friend's name. In June 1826, she was in correspondence with the Italian engraver Giovanni Paolo Lasinio Junior, respecting the publication of her husband's drawings in Florence.
Cosway died in 1838 at her school near Lyons.
From 1995 to 1996, the National Portrait Gallery in London held an exhibition entitled Richard and Maria Cosway: Regency Artists of Taste and Fashion, with 250 works on display.
Cosway drew The Progress of Female Dissipation and The Progress of Female Virtue, published in 1800; besides, she brought out a series of 12 designs, entitled The Winter's Day contributed to Boydell's Shakespeare Gallery and Macklin's Poets. She etched all the plates in a large folio work bearing the following title: Gallery of the Louvre, represented by etchings executed solely by Mrs. Maria Cosway, with an Historical and Critical Description of all the Pictures which compose the Superb Collection, and a Biographical Sketch of the Life of each Painter, by J. Griffiths, &c. &c., (1802), and numerous other plates, some in soft-ground etching, most of which are held in the British Library.