Interestingly (to me) Haydn's operas are the subject of this week's BBC Radio 3 Composer of the Week series...
Yes, he wrote operas. Conductor Antal Dorati went about recording almost all of them about forty years ago or so, too. Unlike the composer's 100-plus symphonies though - which he also recorded, his set has practically no competition, and nothing by way of complete sets under one conductor etc. etc. ...
Eric