Legislative Assembly, national parliament of France during part of the Revolutionary period and again during the Second Republic. The first was created in September 1791 and was in session from Oct. 1, 1791, to Sept. 20, 1792, when it was replaced by the National Convention, marking the formal beginning of the (First) Republic. During the Second Republic it lasted from May 28, 1849, to Dec. 2, 1851, when Napoleon III dissolved it; the republic itself ended less than one year later.