Many big changes took place in France during the Revolution. In 1791 a Constitution was put into place, making France a Constitutional monarchy. This meant that there was a governing Constitution which even the King must follow, as well as a legislative body, called the Legislative Assembly. France began a war with Austria in 1792, which would lead to a series of wars across Europe. In October of 1792, the monarchy was abolished and a Republic of France created. This would become Year 1 of the new French calendar, which was developed the next year. The Legislative Assembly was removed, and a new National Convention became the primary governing body of France. It would be the National Convention who would first make the metric system law, 5 years after its first proposal by Talleyrand. While the people of France were not required to use the metric system, it became the official system of measurement of the Republic of France. The move to make the use of the metric system required by all would not come until many years later, when many other changes had come to France.
In August of 1795, the National Convention came to its end. The Reign of Terror, directed by Maximilien Robespierre, was ended and a new Constitution was written. The new legislative body was called the Directory, and would be in power until 1799, when Napolean Bonaparte took over France. In December of 1799, Napolean made the metric system compulsory, so that everyone in France must use it.