It is uncertain where or exactly when Mozart composer the Piano Sonata No. 11 in A major, K. 331 (300i), however it was most likely in Vienna or Salzburg around 1783. The sonata was published by Artaria in 1784, alongside sonata numbers 10 and 12 (K. 330 and K. 332).
As any good artist does, Max Reger used the first movement theme in his Variations and Fugue on a Theme by Mozart (1914) for orchestra.
In 2014, a Hungarian musicologist discovered four pages of Mozart's original score of the sonata in Budapest's National Széchényi Library. The paper and handwriting of the four pages matched that of the final page of the score, held in Salzburg. The original score is close to the first edition, published in 1784, but differs from later editions.