Ancient state that once ruled the Western world.
It centred on the city of Rome from the founding of the republic (509 BC) through the establishment of the empire (27 BC) to the final eclipse of the empire in the west (5th century AD). The republic's government consisted of two consul s, the Senate , and magistrates, originally all patrician s, and two popular plebeian assemblies: the military centuriate assembly and the civilian tribal assembly. A written code, the Law of the Caesar took power as dictator . Following his assassination (44 BC), conflict among the triumvirs
Mark Antony , Lepidus , and Octavian
ultimately resulted in Octavian's victory (31) and his accession as Emperor {{link=Augustus, Caesar">Augustus (r. 27 BC–AD 14). The imperial government, a principate, combined aspects of the republic and a monarchy. In AD 395 the empire split into eastern and western halves, with the west under severe pressure from the barbarians. Rome was sacked in 410 by the Visigoth s, and the western empire fell to German invaders in 476; the east continued as the Byzantine Empire until 1453. See table.