What Did Mozart Die Of at 35? The Fevered Last Year Behind the Unfinished Requiem

Nobody knows for certain what Mozart died of. He died in Vienna on 5 December 1791, aged just 35, and researchers have since suggested more than a hundred possible causes, from rheumatic fever and a streptococcal infection to trichinosis, influenza and mercury poisoning. The official record called it hitziges Frieselfieber, a "severe miliary fever", which describes a symptom (fever with a rash) rather than a real diagnosis. What we do know is that he died in the middle of one of the most productive years of his life, with an unfinished Requiem on his desk, and that the legends that grew around his death are often more famous than the facts.

A prodigy from Salzburg

Wolfgang Amadeus Mozart was born on 27 January 1756 in Salzburg, then the capital of an independent church principality, in a house on the Getreidegasse. He was the youngest of seven children, five of whom died in infancy. His father, Leopold Mozart, was a court musician and an ambitious teacher, and he was the only teacher Wolfgang and his older sister Maria Anna, known as Nannerl, ever had.

Leopold quickly realised that his son was extraordinary. In 1762, when Wolfgang was about six, the children performed at the Bavarian court in Munich and then at the imperial court in Vienna. A tour of about three and a half years followed, taking the family to Munich, Mannheim, Paris, London, The Hague, Amsterdam, Zurich and many smaller courts. Along the way, at the age of eight, Wolfgang wrote his first symphony.

Between 1769 and 1771 father and son travelled through Italy, the homeland of opera. In Bologna the teenager was admitted to the prestigious Accademia Filarmonica. Childhood on the road made Mozart a cosmopolitan musician who absorbed every style he heard, but it also meant he grew up in carriages and inns, often ill and always performing.

Escaping Salzburg, with a kick

Back home, Mozart took a job in 1773 as a court musician for the Prince-Archbishop of Salzburg, Hieronymus Colloredo. He felt underpaid and underused. Salzburg had no real opera house, and Colloredo treated his musicians as servants.

The tension finally exploded in 1781, during a visit to Vienna with the archbishop's household. After repeated quarrels Mozart was dismissed, according to his own account, "with a kick in the arse" from the archbishop's steward. Instead of returning home in disgrace, he stayed in Vienna and became a freelance performer and composer, a risky choice at a time when most musicians depended on a single court or church.

Vienna: love, success and debt

In Vienna Mozart had his first big operatic success with Die Entführung aus dem Serail (The Abduction from the Seraglio), premiered on 16 July 1782. A few weeks later, on 4 August 1782, he married Constanze Weber in St Stephen's Cathedral, against his father's wishes. They had six children, but only two survived infancy.

The mid-1780s were his golden years. He gave packed subscription concerts, wrote piano concertos for himself to play, and became friends with Joseph Haydn, to whom he dedicated six string quartets. Haydn told Leopold that his son was "the greatest composer known to me by person and repute". Le nozze di Figaro premiered successfully in Vienna in 1786, and Don Giovanni followed in Prague in October 1787.

Yet money was a constant worry. In December 1787 the emperor appointed him chamber composer, with a salary of 800 florins a year, but his income later fell sharply. The biographer Maynard Solomon estimates that his income in 1788 was about two-thirds lower than in 1781, and Mozart borrowed repeatedly, most often from his friend Michael Puchberg.

1791: the last, astonishing year

Mozart's final year was anything but quiet. He composed Die Zauberflöte (The Magic Flute), which played to full houses in his lifetime, along with other major works. His finances were also beginning to recover. That is part of why his sudden death still feels so shocking: he was not a forgotten, broken man, but a composer at the height of his powers.

In the same year he accepted a mysterious-sounding commission: a Requiem Mass. It had been ordered anonymously, through intermediaries, by Count Franz von Walsegg, an amateur musician who liked to pass off commissioned works as his own. The count wanted it to mark the first anniversary of the death of his young wife, Anna. Mozart received half the fee in advance and began work in late 1791.

The final illness

Mozart fell ill in Vienna in late November 1791 and was confined to bed. According to an account by his sister-in-law Sophie, the Requiem lay on his bed covers in his final hours while he explained to his pupil Franz Xaver Süssmayr how it should be finished. He died shortly before 1 a.m. on 5 December.

Because the doctors of the time described symptoms rather than diseases, modern researchers have had only fragments to work with, which explains the long list of proposed causes. Most serious explanations point to an illness, such as an infection or a kidney-related condition, rather than anything sinister.

Was Mozart poisoned by Salieri?

Almost certainly not. The famous idea that the court composer Antonio Salieri poisoned his rival comes from literature, not evidence. Alexander Pushkin's 1830 play Mozart and Salieri turned the rumour into drama; it inspired an opera by Rimsky-Korsakov and, much later, Peter Shaffer's 1979 play Amadeus and the film based on it.

Another popular myth says that Mozart was thrown into a pauper's grave. In fact, the "common grave" in which he was buried was an individual grave for an ordinary citizen, not a mass grave for the poor. Such graves could be dug up after ten years, which is one reason the exact location of his remains is unknown.

Who finished the Requiem?

When Mozart died, only the opening movement, the Introitus, was fully complete. His widow Constanze needed the rest of the fee, so she quietly arranged for others to finish it. The composer Joseph Eybler worked on it first but gave up. Süssmayr then completed the Lacrymosa, orchestrated earlier sections and added the Sanctus, Benedictus and Agnus Dei.

Constanze also helped spread romantic stories: that a mysterious messenger had commissioned the work, and that Mozart believed he was writing his own funeral music. These tales made the Requiem more valuable to publishers, and they still shape how many people hear it today.

A legacy of more than 800 works

In just 35 years Mozart wrote more than 800 works, including operas, symphonies, concertos, chamber music and church music. Together with Haydn's, his music is seen as the model of the Classical style. In 1862 Ludwig Ritter von Köchel published the first catalogue of his works, which is why pieces are still identified by "K" or "KV" numbers, such as the Requiem, K. 626. The publication of his music also rescued Constanze and her two sons from poverty.

The mystery of his death will probably never be solved. But the more useful question is not how he died; it is how a man who died so young managed to leave so much.

Learn with Mozart: English phrases about time and talent

Phrase	Meaning	Example
a child prodigy	a child with an exceptional talent	She was a child prodigy at chess.
at the height of his powers	at the best point of his career	He wrote his best book at the height of his powers.
to make ends meet	to have just enough money to live	Many artists struggle to make ends meet.
a race against time	an effort to finish before it is too late	Finishing the project became a race against time.
to cut short	to end something earlier than expected	His career was cut short by illness.

Try this: Mozart packed a lifetime into 35 years. Write three English sentences about something you want to finish this year, using "before", "by the end of" and "in time to". Then read them aloud with a piece of Mozart playing in the background.