Poland

The Constitution of May 3 was the first law of its kind in Europe and the second in the world.

An excerpt from the article 31 facts about Poland
It was adopted on May 3, 1791, but was in force for only 14 months. It lost its significance when Stanisław August Poniatowski joined the Targowicki Confederation on July 24, 1792. Finally, it ceased to be a binding legal act in the Sejm of Grodno on November 23, 1793.