[1] Written in 1798, it is one of the six late masses by Haydn for the Esterhazy family composed after taking a short hiatus, during which elaborate church music was inhibited by the Josephinian reforms of the 1780s.

[3] Later editors and arrangers added what they perceived to be missing woodwind parts, but the original scoring has again become the accepted choice for modern performances.

What Haydn did not know when he wrote the mass, but what he and his audience heard (perhaps on September 15, the day of the very first performance), was that on 1 August, Napoleon had been dealt a stunning defeat in the Battle of the Nile by British forces led by Admiral Horatio Nelson.

The title became indelible when, in 1800, Lord Nelson himself visited the Palais Esterházy, accompanied by his British mistress, Lady Hamilton, and may have heard the mass conducted by Haydn whom he would meet shortly afterwards.

[4] Haydn's original title may also have come from illness and exhaustion at this time, which followed his supervision of the first performances of The Creation, completed a few months earlier.