トリブス民会
After the founding of the empire, the tribal divisions of citizens and freedmen continued, but the only political purpose of the tribal divisions was such that they better enabled the senate to maintain a list of citizens. Tribal divisions also simplified the process by which grain was distributed. Eventually, most "freedmen" belonged to one of the four urban tribes, while most "freemen" belonged to one of the thirty-one rural tribes. Under the emperor Tiberius, the electoral powers of the Tribal Assembly were transferred to the senate. Each year, after the senate had elected the annual magistrates, the Tribal Assembly also heard the "renuntiatio". Any legislation that the emperor submitted to the assemblies for ratification were submitted to the Tribal Assembly. The assembly ratified imperial decrees, starting with the emperor Augustus, and continuing until the emperor Domitian. The ratification of legislation by the assembly, however, had no legal importance as the emperor could make any decree into law, even without the acquiescence of the assemblies. Thus, under the empire, the chief executive again became the chief lawgiver, which was a power he had not held since the days of the early republic.