Oath of the Tennis Court
20 June 1789, a few hundred deputies representing commoners (as opposed to aristocrats) of the former kingdom of France were stopped from gathering in a place near the Palace of Versailles.
Those representatives suspected it was a deliberate effort from the king to stop them so they headed towards another location and settled for a tennis court (literally a place where an old form of tennis was played)!
In that room, the deputies swore they would meet no matter where until they had written a constitution, and they called themselves the National Assembly!
In my humble opinion, this is the greatest moment of the French Revolution! I never tire of telling this story during my historic walk! Next time you are in Paris, come join the party!