Bach, my all time favourite. An absolute genius; his work was almost forgotten, thank goodness it was rediscovered and preserved. Excellent performance of Prelude and Fugue in C Minor; two pieces I played back in the day for RCM Grade exams.
I don't know about "forgotten"... certainly it was unpopular for quite awhile but composers at least always knew of him and his work. Bach was one of the only older composers that Mozart admired, for example.
Well, that's true, the masters didn't forget about Bach even though the public mostly ignored it. Thankfully Mozart, Beethoven and Mendelssohn helped to keep an appreciation of Bach's work alive.