On Tuesday, June 21, 1791, as the secretary prepared to read the procèsverbal, the president of the National Assembly, Alexandre de Beauharnais, took the floor to announce to its astonished members that at eight o'clock that morning the mayor of Paris had appeared at Beauharnais's residence to apprise him of the departure of the king and the royal family. Thus began an episode that would become one of the finest hours of the National Assembly, yet would also precipitate some of its least defensible actions. The crisis provoked by the king's flight cast a pall over the completion of the constitution, vitiated somewhat its grandeur – if not its moral force – and resulted in an awkward and anticlimactic conclusion to the Assembly's work.

The National Assembly had good reason to be puzzled and surprised. The sense of common purpose arising from the Fête de la Fédération had generated a strong sense of affection for the monarch and maintained belief in a unity of outlook that Louis had only recently reaffirmed.