What is tennis court oath?

The Tennis Court Oath was a result of the growing discontent of the Third Estate in France in the face of King Louis XVI's desire to hold onto the country's
The Tennis Court Oath was a pledge signed by all but one of the members of France's Third Estate, on June 20, 1789, after they had been locked out of a meeting of the Estates General. This group had formed the National Assembly three days earlier on June 17, 1789.