Haydn’s Symphony No.100 was first performed on 31 March 1794 at the Hanover Square Rooms under the direction of Salomon as concertmaster with the composer himself at the fortepiano. The work was an instant success and was repeated a week later on 7 April as reported here:
“[...] a new Symphony, by Haydn, was performed for the second time; and the middle movement [the Allegretto] was again received with absolute shouts of applause. Encore! Encore! Encore! Resounding from every seat [...] It is the advancing to battle; and the march of men, the sounding of the charge, the thundering of the onset, the clash of arms, the groans of the wounded, and what may well be called the hellish roar of war increase to a climax of horrid sublimity! Which, if others can conceive, he alone can execute; at least he alone hitherto has effected these wonders.”
It is clear from this account how the soubriquet ‘Military’ became associated with the work from almost the beginning of its performance history though it is important to remember that, however apt, the title does not stem from Haydn himself.