In ancient Rome, a gens (// or //; plural: "gentes") was a family consisting of individuals who shared the same nomen and who claimed descent from a common ancestor. A branch of a gens was called a stirps (plural: stirpes). 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 membership in a gens declined considerably in imperial times, although the gentilicium continued to be used and defined the origins and dynasties of Roman emperors.