Georg Nikolaus von Nissen (sometimes Nicolaus; 22 January 1761 – 24 March 1826) was a Danish diplomat and music historian.
[1] In 1797, while serving in this post, Nissen first met Mozart's widow, Constanze, whose husband had died six years earlier in 1791.
In this she was successful, obtaining a pension from the Emperor, and making considerable money from concerts of Mozart's music and sale to publishers of his works in manuscript.
The wedding took place in St Martin's Cathedral, Pressburg (today Bratislava), to which the foreign diplomatic corps had temporarily decamped when Napoleon's armies took Vienna.
[7] The completion of the work, based on his notes, was left to a medical doctor and Mozart enthusiast living in Pirna, Johann Heinrich Feuerstein (1797–1850).
[8] Angermüller and Stafford call Feuerstein "unstable" and Halliwell judges his work thus: "the book was cobbled together in a haphazard fashion from the raw material, and the result was disastrous in terms of quality.
"[7] Angermüller and Stafford similarly call the work "problematic", adding that "large sections are taken from earlier accounts, often of dubious reliability, and it contains contradictions and errors.
Nach Originalbriefen, Sammlungen alles über ihn Geschriebenen, mit vielen neuen Beylagen, Steindrücken, Musikblättern und einem Facsimile.
In the foreword to his biography he explains: There is a need for a lot of selection to extract something attractive and characteristic in the letters, which can be offered to the public, without harming the fame and the esteem of the name-human.