Answer:
The Tennis Courth Oath was the starting point of the French Revolution, held on June 20, 1789 by the members of the Third Estate, who decided to remain together until forming a Constitution for France.
In the period before the French Revolution, France was in crisis: internal deficit, external debt, bankruptcy of French factories and the Great Famine of 1787-1789.
The King had summoned the Assembly of General Estates to find a solution to this economic and social crisis in France. The Third Estate, then, pressed the assembly to vote for deputies, instead of being by estate. This removed the guarantee of victory of the king on the votes. Thus, the king closed the Assembly, causing revolt between the bourgeoisie and the people.
Then the bourgeoisie, the lower clergy, and the sans-culottes gathered in the hall of the Jeu de Paume, and together they decided to form a Constituent Assembly to create a new constitution that would restrain the king's power.