Conversation so far:
where was the first hot air balloon invented
The first untethered manned hot air balloon flight was performed in Paris, France.
who was the first hot air balloon flight performed by
The first untethered manned hot air balloon flight was performed by Jean-François Pilâtre de Rozier and François Laurent d'Arlandes.

Question: when was the flight performed
Self-contained rewrite: when was the first hot air balloon flight performed