The Society of the Friends of the Constitution , after 1792 re-named Society of the Jacobins, Friends of Freedom and Equality , commonly known as the Jacobin Club (Club des Jacobins) or just collectively Jacobins (, ), was the most famous and influential political club in the development of the French Revolution. Initially founded by anti-Royalist deputies from Brittany, the Club grew into a nationwide republican movement, with a membership estimated at a half million or more. The Jacobin Club was heterogeneous and included both prominent parliamentary factions of the early 1790s, the radical Mountain and the more moderate Girondists.