On 20 June 1789, the members of the French Third Estate took the Tennis Court Oath (French: Serment du Jeu de Paume), vowing "not to separate and to reassemble wherever circumstances require, until the constitution of the kingdom is established". It was a pivotal event in the French Revolution. The Estates-General had been called to address the country's fiscal and agricultural crisis, but they had become bogged down in issues of representation immediately after convening in May 1789, particularly whether they would vote by order or by head (which would increase the power of the Third Estate, as they outnumbered the other two estates hugely).
On 17 June, the Third Estate began to call themselves the National Assembly, led by Honoré Gabriel Riqueti, Comte de Mirabeau. On the morning of 20 June, the deputies were shocked to discover that the chamber door was locked and guarded by soldiers. They immediately feared the worst and were anxious that a royal attack was imminent from King Louis XVI, so the deputies congregated in a nearby indoor jeu de paume court in the Saint-Louis district of the city of Versailles near the Palace of Versailles. There 576 of the 577 members from the Third Estate took a collective oath "not to separate, and to reassemble wherever circumstances require, until the constitution of the kingdom is established". The only person who did not joined in the oath was Joseph Martin-Dauch from Castelnaudary, who would only execute decisions that were made by the king.
Before the Revolution, French society--aside from royalty--was divided into three estates. The First Estate comprised the clergy; the Second Estate was the nobility. The rest of France--some 98 per cent of the population--was the Third Estate, which ranged from very wealthy city merchants to impoverished rural farmers. The three estates met from time to time in the Estates General, a legislative assembly.
The third Estate comprised the overwhelming majority of the French population but the structure of the Estates-General was such that the Third Estate comprised a bare majority of the delegates. A simple majority was sufficient--as long as delegates' votes were cast together. The First and Second Estates preferred to divide the vote; a proposal might need to receive approval from each Estate or there might be two "houses" of the Estates-General (one for the first two Estates, and one for the Third) and a bill would need to be passed by both houses. Either way, the First and Second Estates could exercise a veto over proposals enjoying widespread support among the Third Estate, such as reforms that threatened the privileges of the nobility and clergy.
The deputies' fears, even if wrong, were reasonable and the importance of the oath goes above and beyond its context. The oath was a revolutionary act and an assertion that political authority derived from the people and their representatives rather than from the monarchy. Their solidarity forced Louis XVI to order the clergy and the nobility to join the Third Estate in the National Assembly to give the illusion that he controlled the National Assembly. This oath was vital to the Third Estate as a protest that led to more power in the Estates General, every governing body thereafter.
An English-language translation of the oath reads:
The National Assembly,
Considering that it has been called to establish the constitution of the realm, to bring about the regeneration of public order, and to maintain the true principles of monarchy; nothing may prevent it from continuing its deliberations in any place it is forced to establish itself; and, finally, the National Assembly exists wherever its members are gathered.
Decrees that all members of this Assembly immediately take a solemn oath never to separate, and to reassemble wherever circumstances require until the constitution of the realm is established and fixed upon solid foundations; and that said oath having been sworn, all members and each one individually confirms this unwavering resolution with his signature.
We swear never to separate ourselves from the National Assembly, and to reassemble wherever circumstances require until the constitution of the realm is drawn up and fixed upon solid foundations.
The Oath signified for the first time that French citizens formally stood in opposition to Louis XVI and the National Assembly's refusal to back down forced the king to make concessions. It was foreshadowed by and drew considerably from the 1776 United States Declaration of Independence, especially the preamble. The Oath also inspired a wide variety of revolutionary activities in the months afterwards, ranging from rioting in the French countryside to renewed calls for a written constitution. It reinforced the Assembly's strength, and although the King attempted to thwart its effect, Louis was forced to relent and on 27 June 1789 he formally requested that voting occur based on head counts, not each estates' power. The Tennis Court Oath (20 June 1789) preceded the abolition of feudalism (4 August 1789) and the Declaration of the Rights of Man and Citizen (26 August 1789).