Maria Constanze Cäcilia Josepha Johanna Aloysia Mozart (née Weber; 5 January 1762 – 6 March 1842) was a German soprano, later a businesswoman.

She is best remembered as the spouse of the composer Wolfgang Amadeus Mozart, who from the evidence of his letters was deeply in love with her throughout their nine-year marriage.

All four were trained as singers and Josepha and Aloysia both went on to distinguished musical careers, later on performing in the premieres of a number of Mozart's works.

During most of Constanze's upbringing, the family lived in her mother's hometown of Mannheim, an important cultural, intellectual and musical center.

[2] By the time Mozart moved to Vienna in 1781, Aloysia had married Joseph Lange, who agreed to help Cäcilia Weber with an annual stipend; she also took in boarders to make ends meet.

[3] On first arriving in Vienna on 16 March 1781,[4] Mozart stayed at the house of the Teutonic Order with the staff of his patron, Archbishop Colloredo.

[9] Mozart wrote to Leopold on 31 July 1782, "All the good and well-intentioned advice you have sent fails to address the case of a man who has already gone so far with a maiden.

The letters are unfailingly affectionate, often intensely so; and at times they can also be solicitous, supervisory, erotic, or silly; the general sense they give is of a happy marriage.

Just imagine that little sneak, while I am writing he has secretly crept up on the table and now looks at me questioningly; but I, without much ado, give him a little slap--but now he is even more [ word erased by some unknown hand ]; well, he is almost out of control, the scoundrel.

However, in her old age she remembered her marriage to Mozart (as well as her later marriage to Nissen) as very happy; she wrote in a letter to a music teacher named Friedrich Schwaan (5 December 1829): "I have had two most excellent husbands by whom I was loved and honoured – even, I have to say, adored; they, too were both equally loved by me with the utmost tenderness, thus I was twice completely happy.”[19] Mozart died in 1791, leaving debts and placing Constanze in a difficult position.

At this point Constanze's business skills came into fruition: she obtained a pension from the emperor, organized profitable memorial concerts, and embarked on a campaign to publish the works of her late husband.

Among Constanze's musical accomplishments in the years after Mozart's death was her promulgation of his late opera La Clemenza di Tito, which had been prepared for performance in Prague in 1791.

She mounted a benefit performance on 29 December 1794 at the Kärntnertortheater in Vienna, with her sister Aloysia Weber taking the role of Sextus.

The extraordinary writing for soprano solo in the Great Mass in C minor (for example, in the "Christe eleison" section of the Kyrie movement, or the aria "Et incarnatus est") was intended for Constanze, who sang in the 1783 premiere of this work in Salzburg.

During the period of the couple's courtship, Mozart began making visits to Baron Gottfried van Swieten, who let him examine his extensive collection of manuscripts of work by Bach and Handel.

Baron van Swieten, to whom I go every Sunday, gave me all the works of Händel and Sebastian Bach to take home with me (after I had played them to him).

[27]According to the Grove Dictionary of Music and Musicians, Constanze has been treated harshly and unfairly by a number of her biographers: "Early 20th-century scholarship severely criticized her as unintelligent, unmusical and even unfaithful, and as a neglectful and unworthy wife to Mozart.

[32] The Royal Conservatory of Brussels conserves several autograph documents from Constance Mozart, including letters to her son Franz Xaver Wolfgang Mozart, as well as a small illustrated Album de Souvenirs, dated 1789 but covering the 1801–1823 period in which she collects memories, impressions and poems (ref.