Tribal Assembly
According to legend, the Roman King Servius Tullius enacted a series of constitutional reforms in the 6th century BC. One of these reforms resulted in the creation of a new organizational unit with which to divide citizens. This unit, the "Tribe", was based on geography rather than family, and was created to assist in future reorganizations of the army. In 471 BC, a law was passed which allowed the Plebeians to begin organizing by Tribe. Before this point, they had organized on the basis of the "Curia". The only difference between the Plebeian Council after 471 BC and the ordinary "Tribal Assembly" (which also organized on the basis of the Tribes) was that the Tribes of the Plebeian Council only included Plebeians, whereas the Tribes of the Tribal Assembly included both Plebeians and Patricians.