Today, Friday, June 20, 2014, marks the 225th anniversary of the serment du jeu de paume — the tennis court oath — a key event at the start of the French Revolution. On June 17, 1789, the 577 members of the Third Estate, who had begun calling themselves the National Assembly, were locked out of a meeting of the Estates-General, presumably because King Louis XVI (who had the keys) was displeased with the direction of their discussions.

This is a pattern often observed among kings who are losing power.

In need of an alternate venue, the delegates found their way to a tennis court located in the Saint-Louis District of Versailles near the palace.

There, all but one of the delegates agreed “not to separate, and to reassemble wherever circumstances require, until the Constitution of the kingdom is established”.

In the ensuing two months or so, the Bastille would fall (July 14), feudalism would be abolished (August 4) and the Rights of Man and Citizen would be declared (August 26).

It was a big day in the evolution of government, but there was more.

The tennis court in the picture, a faithful reproduction of the one in Versailles, does not look like tennis courts, as most people know them today. Those would not come into being until 1873, more than 80 years later.

The tennis courts of the time were indoors and surrounded by walls. Approximately 45 of them still exist and are in use today in England, France, the United States and Australia. Today, to celebrate the biggest event ever to occur in a tennis court, each of those micro-sport venues celebrates International Tennis Day.

Two interesting questions arise from the image of 577 people, perhaps frightened of being punished by the King, gathering in a large empty room.

Since there were no chairs, with whom would the delegates choose to stand?

How did they get in?

Human nature answers the first question. The delegates would tend to congregate among those with whom they agreed. Well, perhaps with the exception of Joseph Martin-Dauch, the sole delegate who refused to execute a decision not sanctioned by the King. In the famous Jacques-Louis David drawing, Martin-Dauch is depicted in the lower right-hand corner holding his head in his hands.

With thanks to Frederika Adam, here is the answer to the second question. The delegates walked through a door. It looked just like this.

Now combine the two answers. The delegates walked through a door and chose to congregate among those with whom they agreed.

Some went left and some went right, and today also marks the 225th anniversary of the origin of the words left wing and right wing as they are applied to politics throughout the world.