On July 9th, 1789. Right after the Tennis court oath.
Source:
http://bastille-day.com/history/Estates-General-1789
The National Assembly was formed by the representatives of the Third Estate of the Estates General. After the French Revolution the National Assembly became known as the National Constituent Assembly.
The Legislative Assembly, as a significant political body, was notably established during the French Revolution in 1791. It succeeded the National Constituent Assembly and operated until 1792, when it was replaced by the National Convention. The assembly was responsible for enacting laws and addressing various issues during a tumultuous period in French history.
National Assembly
National Assembly of Soviets was created in 1919.
National Assembly of Soviets ended in 1919.
National Assembly of Cambodia was created in 1993.
National Assembly of Bulgaria was created in 1886.
National Assembly of Women was created in 1952.
National Assembly Building was created in 1975.
Great National Assembly was created in 1948.
Great National Assembly ended in 1989.
National Assembly of Eritrea was created in 1992.