The Symphony No. 8 in D major,, by Wolfgang Amadeus Mozart is dated 13 December 1768. Mozart wrote the symphony in Vienna, when he was 12 years old, at a time when he and his family were already due to have returned home to Salzburg. In a letter to his friend in Salzburg, Johann Lorenz Hagenauer, Leopold Mozart says of the delay that "we could not bring our affairs to a conclusion earlier, even though I endeavored strenuously to do so." The autograph of the Symphony No. 8 is today preserved in the Berlin State Library.