In June of 1789, the third estate of France began to call themselves the national assembly. On the morning of June 20, the deputies were shocked to discover the chamber door locked and guarded by soldiers. They feared that an attack by the King was imminent. The deputies congregated in a nearby indoor court in the St. Louis district of the city of Versailles, near the palace.
The third estate took a collective oath not to separate, and to reassemble whenever circumstances allowed until the constitution of the kingdom was enacted. It was a dramatic act of defiance by representatives of the non-privileged classes of the French nation.