The official names of the Senate and the Roman people can be used to represent all the land under the rule of the Roman Empire. The expansion of Rome made Rome surpass the concept of city-state and become an empire. The heyday of Roman territory was the reign of Trajan. At this time, the Roman Empire controlled about 5.9 million square kilometers of land, making it one of the largest countries in the ancient history of the world.

After Octavian established the empire, he founded the head of state system called Augustus. The Roman Empire is generally divided into two stages: the early empire (-192) and the late empire (193-476). The early empire reached its peak through the Jorio-Claudia dynasty, the Flavian dynasty and the Antoine dynasty (the era of five wise emperors). National stability and social prosperity are called the golden age of Rome. Later empires, from the crisis of the third century, were ruled by the emperors of Illyria, Diocletian and Constantine the Great, and were formally divided into two parts after the death of Theodosius I (395). In 476, Odiak deposed the last emperor of the Western Roman Empire, romulus Augustus Orus, and the Western Roman Empire perished. The Eastern Roman Empire was destroyed by the Ottoman Empire until 1453, and historians called it the Byzantine Empire. 509 years ago, Rome established the Roman Republic. In the 2nd century BC, Rome became the overlord of the Mediterranean. In 49 BC, Caesar, a military general, seized power. In 27 BC, Octavian established the head of state system, and Rome entered the Roman Empire. From about 370, Rome was divided into the Western Roman Empire and the Eastern Roman Empire. The capital of the Western Roman Empire is in Meti Ollanu (now Milan), and the capital of the Eastern Roman Empire is in Constantinople. However, it is intriguing that the eastern and western Roman empires are not hostile to each other, but closely cooperate in many aspects. Since then, during the period of 100, Rome has been conquered by foreigners for many times, and the strength and majesty of the western Roman empire have plummeted. In 476 AD, the Western Roman Empire disintegrated, and the last Roman emperor personally issued a letter of abdication, announcing that the Western Roman Empire no longer existed and all the colonies of the Empire could be independent on their own. The Eastern Roman Empire was preserved, which became the "Byzantine Empire". Although the Western Roman Empire collapsed in 476, its emperor was deposed by the Germans. However, the Roman rule in Paris lasted until 486, when Clovis, the Frankish of the Germanic nation, completely defeated the Romans and established the Frankish Kingdom, the predecessor of France. Later, the Frankish kingdom continued to grow and develop, reaching its peak in 800 under Charlemagne's rule of Caroline dynasty, unifying the territories of France, Germany, Netherlands, Switzerland, northern Italy, western Austria and the northeast corner of Spain, which was called Charlemagne Empire in history. The treatment of the Roman army is quite good. Emperor Severus once said, "Let the soldiers get rich and leave others alone." The expansion of the Roman Empire and its influence At the beginning of the 3rd century BC, the Romans unified the Italian peninsula and became a Mediterranean power. From then on, Rome began a long-term process of external expansion. The first object of Rome's expansion was Carthage, a powerful Mediterranean country at that time. It successively captured Sicily, Corsica, Sardinia and some places south of the Alps, and finally captured Carthage and its rule. At the same time, Rome is still expanding eastward. It controlled Greece through three wars with Macedonians. Then he invaded Syria and took control of parts of West Asia. In the west, the Romans also occupied many places. Today, many parts of European countries such as France and Spain are incorporated into the territory of Rome. During the reign of Caesar, he also sent troops to invade Britain twice. Octavian led the Roman army again. In the second half of the 2nd century BC, Rome has become a big country spanning Europe, Asia and Africa. At that time, the territory of the Roman Empire started from the upper reaches of the Euphrates River in the east, to the Atlantic Ocean in the west, to the Sahara Desert in Africa in the south, and to the Rhine and Danube in the north.