The Civil Constitution of the Clergy was a law passed in 1790 during the French Revolution that restructured the Catholic Church in France, making it a part of the state. This legislation aimed to reduce the power of the Catholic Church, aligning its administration with the principles of the Revolution by requiring clergy to take an oath of loyalty to the state rather than to the pope. It caused significant conflict within France and between the revolutionary government and the Church, leading to a split among Catholics and contributing to tensions during this transformative period.