Mozart dedicated his Haydn quartets to Haydn in 1785, which was an unusual decision, as most dedicatees were aristocrats, and Haydn did not become a prominent public figure, let alone aristocrat, until at least 1795.
Mozart's dedication of these six quartets to Haydn was rather unusual, at a time when dedicatees were usually aristocrats: Haydn returned to Vienna in 1795. By this time Haydn had become a public figure in Vienna. With the increase in his reputation, Haydn eventually obtained aristocratic patronage, crucial for the career of a composer in his day. 
