Question: Who was the first Emperor of the city that was the center of imperial life in the empire that inspired the Carolingian Empire?

full_context: Document 1: Early Middle Ages: For almost a thousand years, Rome was the most politically important, richest and largest city in Europe. Around 100 CE, it had a population of about 450,000, and declined to a mere 20,000 during the Early Middle Ages, reducing the sprawling city to groups of inhabited buildings interspersed among large areas of ruins and vegetation.
Document 2: Middle Ages: Charlemagne planned to continue the Frankish tradition of dividing his kingdom between all his heirs, but was unable to do so as only one son, Louis the Pious (r. 814–840), was still alive by 813. Just before Charlemagne died in 814, he crowned Louis as his successor. Louis's reign of 26 years was marked by numerous divisions of the empire among his sons and, after 829, civil wars between various alliances of father and sons over the control of various parts of the empire. Eventually, Louis recognised his eldest son Lothair I (d. 855) as emperor and gave him Italy. Louis divided the rest of the empire between Lothair and Charles the Bald (d. 877), his youngest son. Lothair took East Francia, comprising both banks of the Rhine and eastwards, leaving Charles West Francia with the empire to the west of the Rhineland and the Alps. Louis the German (d. 876), the middle child, who had been rebellious to the last, was allowed to keep Bavaria under the suzerainty of his elder brother. The division was disputed. Pepin II of Aquitaine (d. after 864), the emperor's grandson, rebelled in a contest for Aquitaine, while Louis the German tried to annex all of East Francia. Louis the Pious died in 840, with the empire still in chaos.
Document 3: Middle Ages: The High Middle Ages was a period of tremendous expansion of population. The estimated population of Europe grew from 35 to 80 million between 1000 and 1347, although the exact causes remain unclear: improved agricultural techniques, the decline of slaveholding, a more clement climate and the lack of invasion have all been suggested. As much as 90 per cent of the European population remained rural peasants. Many were no longer settled in isolated farms but had gathered into small communities, usually known as manors or villages. These peasants were often subject to noble overlords and owed them rents and other services, in a system known as manorialism. There remained a few free peasants throughout this period and beyond, with more of them in the regions of Southern Europe than in the north. The practice of assarting, or bringing new lands into production by offering incentives to the peasants who settled them, also contributed to the expansion of population.
Document 4: Roman Republic: However, civil war flared again when the Second Triumvirate of Octavian, Lepidus and Mark Antony failed. The ambitious Octavian built a power base of patronage and then launched a campaign against Mark Antony. At the naval Battle of Actium off the coast of Greece, Octavian decisively defeated Antony and Cleopatra. Octavian was granted a series of special powers including sole "imperium" within the city of Rome, permanent consular powers and credit for every Roman military victory, since all future generals were assumed to be acting under his command. In 27 BC Octavian was granted the use of the names "Augustus" and "Princeps", indicating his primary status above all other Romans, and he adopted the title "Imperator Caesar" making him the first Roman Emperor.
Document 5: Roman Empire: The Roman Empire (Latin: Imperium Rōmānum, Classical Latin: (ɪmˈpɛ. ri. ũː roːˈmaː. nũː); Koine and Medieval Greek: Βασιλεία τῶν Ῥωμαίων, tr. Basileia tōn Rhōmaiōn) was the post-Roman Republic period of the ancient Roman civilization, with a government headed by emperors and large territorial holdings around the Mediterranean Sea in Europe, Africa and Asia. The city of Rome was the largest city in the world c. 100 BC -- c. AD 400, with Constantinople (New Rome) becoming the largest around AD 500, and the Empire's population grew to an estimated 50 to 90 million inhabitants (roughly 20% of the world's population at the time). The 500 - year - old republic which preceded it had been severely destabilized in a series of civil wars and political conflict, during which Julius Caesar was appointed as perpetual dictator and then assassinated in 44 BC. Civil wars and executions continued, culminating in the victory of Octavian, Caesar's adopted son, over Mark Antony and Cleopatra at the Battle of Actium in 31 BC and the annexation of Egypt. Octavian's power was then unassailable and in 27 BC the Roman Senate formally granted him overarching power and the new title Augustus, effectively marking the end of the Roman Republic.
Document 6: Rome: Rome's history spans 28 centuries. While Roman mythology dates the founding of Rome at around 753 BC, the site has been inhabited for much longer, making it one of the oldest continuously occupied sites in Europe. The city's early population originated from a mix of Latins, Etruscans, and Sabines. Eventually, the city successively became the capital of the Roman Kingdom, the Roman Republic and the Roman Empire, and is regarded by some as the first ever metropolis. It was first called "The Eternal City" (; ) by the Roman poet Tibullus in the 1st century BC, and the expression was also taken up by Ovid, Virgil, and Livy. Rome is also called the "Caput Mundi" (Capital of the World). After the fall of the Western Empire, which marked the beginning of the Middle Ages, Rome slowly fell under the political control of the Papacy, and in the 8th century it became the capital of the Papal States, which lasted until 1870. Beginning with the Renaissance, almost all the popes since Nicholas V (1447–1455) pursued over four hundred years a coherent architectural and urban programme aimed at making the city the artistic and cultural centre of the world. In this way, Rome became first one of the major centres of the Italian Renaissance, and then the birthplace of both the Baroque style and Neoclassicism. Famous artists, painters, sculptors and architects made Rome the centre of their activity, creating masterpieces throughout the city. In 1871, Rome became the capital of the Kingdom of Italy, which, in 1946, became the Italian Republic.
Document 7: Middle Ages: The coronation of Charlemagne as emperor on Christmas Day 800 is regarded as a turning point in medieval history, marking a return of the Western Roman Empire, since the new emperor ruled over much of the area previously controlled by the western emperors. It also marks a change in Charlemagne's relationship with the Byzantine Empire, as the assumption of the imperial title by the Carolingians asserted their equivalence to the Byzantine state. There were several differences between the newly established Carolingian Empire and both the older Western Roman Empire and the concurrent Byzantine Empire. The Frankish lands were rural in character, with only a few small cities. Most of the people were peasants settled on small farms. Little trade existed and much of that was with the British Isles and Scandinavia, in contrast to the older Roman Empire with its trading networks centred on the Mediterranean. The empire was administered by an itinerant court that travelled with the emperor, as well as approximately 300 imperial officials called counts, who administered the counties the empire had been divided into. Clergy and local bishops served as officials, as well as the imperial officials called missi dominici, who served as roving inspectors and troubleshooters.
Document 8: Charlemagne: Charlemagne (/ ˈʃɑːrlɪmeɪn /) or Charles the Great (2 April 742 -- 28 January 814), numbered Charles I, was King of the Franks from 768, King of the Lombards from 774 and Emperor of the Romans from 800. He united much of Europe during the early Middle Ages. He was the first recognised emperor in western Europe since the fall of the Western Roman Empire three centuries earlier. The expanded Frankish state that Charlemagne founded is called the Carolingian Empire.
Document 9: Roman Republic: After the assassination, Mark Antony formed an alliance with Caesar's adopted son and great-nephew, Gaius Octavian. Along with Marcus Lepidus, they formed an alliance known as the Second Triumvirate. They held powers that were nearly identical to the powers that Caesar had held under his constitution. As such, the Senate and assemblies remained powerless, even after Caesar had been assassinated. The conspirators were then defeated at the Battle of Philippi in 42 BC. Eventually, however, Antony and Octavian fought against each other in one last battle. Antony was defeated in the naval Battle of Actium in 31 BC, and he committed suicide with his lover, Cleopatra. In 29 BC, Octavian returned to Rome as the unchallenged master of the Empire and later accepted the title of Augustus ("Exalted One"). He was convinced that only a single strong ruler could restore order in Rome.
Document 10: Roman Republic: The extensive campaigning abroad by Roman generals, and the rewarding of soldiers with plunder on these campaigns, led to a general trend of soldiers becoming increasingly loyal to their generals rather than to the state. Rome was also plagued by several slave uprisings during this period, in part because vast tracts of land had been given over to slave farming in which the slaves greatly outnumbered their Roman masters. In the 1st century BC at least twelve civil wars and rebellions occurred. This pattern continued until 27 BC, when Octavian (later Augustus) successfully challenged the Senate's authority, and was made princeps (first citizen).
Document 11: Middle Ages: Roman city life and culture changed greatly in the early Middle Ages. Although Italian cities remained inhabited, they contracted significantly in size. Rome, for instance, shrank from a population of hundreds of thousands to around 30,000 by the end of the 6th century. Roman temples were converted into Christian churches and city walls remained in use. In Northern Europe, cities also shrank, while civic monuments and other public buildings were raided for building materials. The establishment of new kingdoms often meant some growth for the towns chosen as capitals. Although there had been Jewish communities in many Roman cities, the Jews suffered periods of persecution after the conversion of the empire to Christianity. Officially they were tolerated, if subject to conversion efforts, and at times were even encouraged to settle in new areas.
Document 12: Middle Ages: The importance of infantry and light cavalry began to decline during the early Carolingian period, with a growing dominance of elite heavy cavalry. The use of militia-type levies of the free population declined over the Carolingian period. Although much of the Carolingian armies were mounted, a large proportion during the early period appear to have been mounted infantry, rather than true cavalry. One exception was Anglo-Saxon England, where the armies were still composed of regional levies, known as the fyrd, which were led by the local elites. In military technology, one of the main changes was the return of the crossbow, which had been known in Roman times and reappeared as a military weapon during the last part of the Early Middle Ages. Another change was the introduction of the stirrup, which increased the effectiveness of cavalry as shock troops. A technological advance that had implications beyond the military was the horseshoe, which allowed horses to be used in rocky terrain.
Document 13: Roman Republic: Caesar was now the primary figure of the Roman state, enforcing and entrenching his powers. His enemies feared that he had ambitions to become an autocratic ruler. Arguing that the Roman Republic was in danger, a group of senators hatched a conspiracy and assassinated Caesar at a meeting of the Senate in March 44 BC.  Mark Antony, Caesar's lieutenant, condemned Caesar's assassination, and war broke out between the two factions. Antony was denounced as a public enemy, and Caesar's adopted son and chosen heir, Gaius Octavianus, was entrusted with the command of the war against him. At the Battle of Mutina Mark Antony was defeated by the consuls Hirtius and Pansa, who were both killed.
Document 14: Roman Empire: The Roman Empire was among the most powerful economic, cultural, political and military forces in the world of its time. It was one of the largest empires in world history. At its height under Trajan, it covered 5 million square kilometres. It held sway over an estimated 70 million people, at that time 21% of the world's entire population. The longevity and vast extent of the empire ensured the lasting influence of Latin and Greek language, culture, religion, inventions, architecture, philosophy, law and forms of government on the empire's descendants. Throughout the European medieval period, attempts were even made to establish successors to the Roman Empire, including the Empire of Romania, a Crusader state; and the Holy Roman Empire. By means of European colonialism following the Renaissance, and their descendant states, Greco - Roman and Judaeo - Christian culture was exported on a worldwide scale, playing a crucial role in the development of the modern world.
Document 15: Military history of France: Under Charlemagne the Franks reached the height of their power. After campaigns against Lombards, Avars, Saxons, and Basques, the resulting Carolingian Empire stretched from the Pyrenees to Central Germany, from the North Sea to the Adriatic. In 800 the Pope made Charlemagne Emperor of the West in return for protection of the Church. The Carolingian Empire was a conscious effort to recreate a central administration modeled on that of the Roman Empire,[13] but the motivations behind military expansion differed. Charlemagne hoped to provide his nobles an incentive to fight by encouraging looting on campaign. Plunder and spoils of war were stronger temptations than imperial expansion, and several regions were invaded over and over in order to bolster the coffers of Frankish nobility.[14] Cavalry dominated the battlefields, and while the high costs associated with equipping horses and horse-riders helped limit their numbers, Carolingian armies maintained an average size of 20,000 by recruiting infantry from imperial territories near theaters of operation.[15] The Empire lasted from 800 to 843, when, following Frankish tradition, it was split between the sons of Louis the Pious by the Treaty of Verdun.
ground_truth: Octavian
sub_queries: What government was the Carolingian Empire inspired by? Answer: the Roman Empire
what city was the center of imperial life in the Roman Empire in the early fifth century Answer: Rome
Who has been designated as the first Emperor of Rome ? Answer: Octavian