In ancient Rome, a gens was a family consisting of individuals who shared the same nomen gentilicium and who claimed descent from a common ancestor. A branch of gens, identified by the cognomen, was called a stirps. The gens was an important social structure at Rome and throughout Italia during the period of the Roman Republic. Much of individuals' social standing depended on the gens to which they belonged. Certain gentes were classified as patrician, others as plebeian; some had both patrician and plebeian branches. The importance of the gens as a social structure declined considerably in imperial times, although the gentilicium continued to define the origins and dynasties of the ancient Romans, including the Emperors.