How many symphonies did Joseph Haydn compose?

There are 106 symphonies by the classical composer Joseph Haydn (1732–1809). Of these, 104 have numbers associated with them which were originally assigned by Eusebius Mandyczewski in 1908 in the chronological order that was known at the time. Eusebius Mandyczewski (18 August 1857, in Molodiia – 13 August 1929, in Vienna) was a Romanian musicologist, composer, conductor, and teacher. He was an author of numerous musical works and is highly regarded within Austrian, Romanian and Ukrainian music circles.

Franz Joseph Haydn was an Austrian composer of the Classical period. He was instrumental in the development of chamber music such as the piano trio. His contributions to musical form have earned him the epithets "Father of the Symphony" and "Father of the String Quartet".

Haydn spent much of his career as a court musician for the wealthy Esterházy family at their remote estate. Until the later part of his life, this isolated him from other composers and trends in music so that he was, as he put it, "forced to become original". Yet his music circulated widely, and for much of his career he was the most celebrated composer in Europe.

He was a friend and mentor of Mozart, a tutor of Beethoven, and the older brother of composer Michael Haydn.