Proper noun
the Tennis Court Oath
(historical) An oath taken on 20 June 1789 by the members of the French Third Estate, who had begun to call themselves the National Assembly, vowing "not to separate, and to reassemble wherever circumstances require, until the constitution of the kingdom is established"; pivotal in the French Revolution.
It thus met at the tennis court in Versailles and took the Tennis Court Oath not to separate before it had given a constitution to the nation. Source: Internet
Drawing by Jacques-Louis David of the Tennis Court Oath. Source: Internet
The Third Estate took the Tennis Court Oath ( le serment du Jeu de paume main, 20 June 1789), swearing not to separate until a constitution had been established. Source: Internet