Julius Caesar in the context of "The Twelve Caesars"

Marcus Porcius Cato (/ˈkɑːtoʊ/, KAH-toe; 234–149 BC), also known as Cato the Censor (Latin: Censorius), the Elder and the Wise, was a Roman soldier, senator, and historian known for his conservatism and opposition to Hellenization. He was the first to write history in Latin with his Origines, a now fragmentary work on the history of Rome. His work De agri cultura, a treatise on agriculture, rituals, and recipes, is the oldest extant prose written in the Latin language. His epithet "Elder" distinguishes him from his great-grandson Senator Cato the Younger, who opposed Julius Caesar.

He came from an ancient plebeian family who were noted for their military service. Like his forefathers, Cato was devoted to agriculture when not serving in the army. Having attracted the attention of Lucius Valerius Flaccus, he was brought to Rome. He was successively military tribune (214 BC), quaestor (204), aedile (199), praetor (198), consul (195) together with Flaccus, and censor (184). As praetor, he expelled usurers from Sardinia. As censor, he tried to save Rome's ancestral customs and combat Hellenistic influences.

During the Second Punic War with Carthage, Rome's earliest known annalists Quintus Fabius Pictor and Lucius Cincius Alimentus recorded history in Greek, and relied on Greek historians such as Timaeus. Roman histories were not written in Classical Latin until the 2nd century BCE with the Origines by Cato the Elder. Contemporary Greek historians such as Polybius wrote about the rise of Rome during its conquest of Greece and ascension as the primary power of the Mediterranean in the 2nd century BCE. Moving away from the annalist tradition, Roman historians of the 1st century BCE such as Sallust, Livy, and even Julius Caesar wrote their works in a much fuller narrative form. While Caesar's De Bello Gallico focused specifically on his wars in Gaul, Roman works that served as a broad universal history often placed heavy emphasis on the origin myth of the founding of Rome as a starting point. These works formed the basis of the Roman historiographic models utilized by later Imperial authors of the Principate era, such as Tacitus and Suetonius.

Cleopatra VII Thea Philopator (Koine Greek: Κλεοπάτρα Θεά Φιλοπάτωρ, lit. 'Cleopatra father-loving goddess'; 70/69 BC – 10 or 12 August 30 BC) was Queen of the Ptolemaic Kingdom of Egypt from 51 to 30 BC, and the last active Hellenistic pharaoh. A member of the Ptolemaic dynasty, she was a descendant of its founder Ptolemy I Soter, a Macedonian Greek general and companion of Alexander the Great. Her first language was Koine Greek, and she is the only Ptolemaic ruler known to have learned the Egyptian language, among several others. After her death, Egypt became a province of the Roman Empire, marking the end of the Hellenistic period in the Mediterranean, which had begun during the reign of Alexander (336–323 BC).

Born in Alexandria, Cleopatra was the daughter of Ptolemy XII Auletes, who named her his heir before his death in 51 BC. Cleopatra began her reign alongside her brother Ptolemy XIII, but a falling-out between them led to a civil war. Roman statesman Pompey fled to Egypt after losing the 48 BC Battle of Pharsalus against his rival Julius Caesar, the Roman dictator, in Caesar's civil war. Pompey had been a political ally of Ptolemy XII, but Ptolemy XIII had him ambushed and killed before Caesar arrived and occupied Alexandria. Caesar then attempted to reconcile the rival Ptolemaic siblings, but Ptolemy XIII's forces besieged Cleopatra and Caesar at the palace. Shortly after the siege was lifted by reinforcements, Ptolemy XIII died in the Battle of the Nile. Caesar declared Cleopatra and her brother Ptolemy XIV joint rulers, and maintained a private affair with Cleopatra which produced a son, Caesarion. Cleopatra traveled to Rome as a client queen in 46 and 44 BC, where she stayed at Caesar's villa. After Caesar's assassination, followed shortly afterwards by the sudden death of Ptolemy XIV (possibly murdered on Cleopatra's order), she named Caesarion co-ruler as Ptolemy XV.

The War of Actium (32–30 BC) was the last civil war of the Roman Republic, fought between Mark Antony (assisted by Cleopatra and by extension Ptolemaic Egypt) and Octavian. In 32 BC, Octavian convinced the Roman Senate to declare war on the Egyptian queen Cleopatra. Her lover and ally Mark Antony, who was Octavian's rival, gave his support for her cause. Forty percent of the Roman Senate, together with both consuls, left Rome to join the war on Antony's side. After a decisive victory for Octavian at the Battle of Actium, Cleopatra and Antony withdrew to Alexandria, where Octavian besieged the city until both Antony and Cleopatra were forced to commit suicide.

The war involved some of the largest Roman armies ever seen. Both Antony and Octavian's legions were experienced veterans of previous civil wars who had fought together, many also having once served under Julius Caesar. The two did however raise their own legions separately.

Marcus Antonius (14 January 83 BC – 1 August 30 BC), commonly known in English as Mark Antony, was a Roman politician and general who played a critical role in the transformation of the Roman Republic from a constitutional republic into the autocratic Roman Empire.

Antony was a relative and supporter of Julius Caesar, and he served as one of his generals during the conquest of Gaul and Caesar's civil war. Antony was appointed administrator of Italy while Caesar eliminated political opponents in Greece, North Africa, and Spain. After Caesar's assassination in 44 BC, Antony joined forces with Lepidus, another of Caesar's generals, and Octavian, Caesar's great-nephew and adopted son, forming a three-man dictatorship known to historians as the Second Triumvirate. The Triumvirs defeated Caesar's killers, the Liberatores, at the Battle of Philippi in 42 BC, and divided the government of the Republic among themselves. Antony was assigned Rome's eastern provinces, including the client kingdom of Egypt, then ruled by Cleopatra VII, and was given the command in Rome's war against Parthia.

A legate (Latin: legatus, Classical Latin: [ɫeːˈɡaːtʊs]) was a high-ranking military officer in the Roman army, equivalent to a modern-era general officer. Initially used to delegate power, the term became formalised under Augustus as the officer in command of a Roman legion.

From the times of the Roman Republic, legates received large shares of the military's rewards at the end of a successful campaign. This made the position a lucrative one, so it could often attract even distinguished consuls or other high-ranking political figures within Roman politics (e.g., the consul Lucius Julius Caesar volunteered late in the Gallic Wars as a legate under his first cousin, Gaius Julius Caesar).

The history of the Roman Empire covers the history of ancient Rome from the traditional end of the Roman Republic in 27 BC until the abdication of Romulus Augustulus in AD 476 in the West, and the Fall of Constantinople in the East in 1453. Ancient Rome became a territorial empire while still a republic but was then ruled by emperors, beginning with Octavian Augustus, the final victor of the republican civil wars.

Rome had begun expanding shortly after the founding of the Republic in the 6th century BC, though it did not expand outside the Italian Peninsula until the 3rd century BC, during the Punic Wars, after which the Republic expanded across the Mediterranean. Civil war engulfed Rome in the mid-1st century BC, first between Julius Caesar and Pompey, and finally between Octavian (Caesar's grand-nephew) and Mark Antony. Antony was defeated at the Battle of Actium in 31 BC, leading to the annexation of Egypt. In 27 BC, the Senate gave Octavian the titles of Augustus ("venerated") and Princeps ("foremost"), thus beginning the Principate, the first epoch of Roman imperial history. Augustus' name was inherited by his successors, as well as his title of Imperator ("commander"), from which the term "emperor" is derived. Early emperors avoided any association with the ancient kings of Rome, instead presenting themselves as leaders of the Republic.

Venus (/ˈviːnəs/; Classical Latin: [ˈwɛnʊs]) is a Roman goddess whose functions encompass love, beauty, desire, sex, fertility, prosperity, and victory. In Roman mythology, she was the ancestor of the Roman people through her son, Aeneas, who survived the fall of Troy and fled to Italy. Julius Caesar claimed her as his ancestor. Venus was central to many religious festivals, and was revered in Roman religion under numerous cult titles.

The Romans adapted the myths and iconography of her Greek counterpart Aphrodite for Roman art and Latin literature. In the later classical tradition of the West, Venus became one of the most widely referenced deities of Greco-Roman mythology as the embodiment of love and sexuality. As such, she is usually depicted nude.

The Parallel Lives (Ancient Greek: Βίοι Παράλληλοι, Bíoi Parállēloi; Latin: Vītae Parallēlae) is a series of 48 biographies of famous men written in Greek by the Greco-Roman philosopher, historian, and Apollonian priest Plutarch, probably at the beginning of the second century. The lives are arranged in pairs to illuminate their common moral virtues or failings.

The surviving Parallel Lives comprises 23 pairs of biographies, each pair consisting of one Greek and one Roman of similar destiny, such as Alexander the Great and Julius Caesar, or Demosthenes and Cicero. There are also four singular Lives, recounting the stories of Artaxerxes, Aratus, Galba, and Otho. Traces of other biographies point to an additional twelve single Lives that are now missing.

The history of Rome includes the history of the city of Rome as well as the civilisation of ancient Rome. Roman history has been influential on the modern world, especially in the history of the Catholic Church, and Roman law has influenced many modern legal systems. Roman history can be divided into the following periods:

• Pre-historical and early Rome, covering Rome's earliest inhabitants and the legend of its founding by Romulus
• The period of Etruscan dominance and the regal period, in which, according to tradition, Romulus was the first of seven kings
• The Roman Republic, which commenced in 509 BC when kings were replaced with rule by elected magistrates. The period was marked by vast expansion of Roman territory. During the 5th century BC, Rome gained regional dominance in Latium. With the Punic Wars from 264 to 146 BC, ancient Rome gained dominance over the Western Mediterranean, displacing Carthage as the dominant regional power.
• The Roman Empire followed the Republic, which waned with the rise of Julius Caesar, and by all measures concluded after a period of civil war and the victory of Caesar's adopted son, Octavian, in 27 BC over Mark Antony.
• The Western Roman Empire collapsed in 476 after the city was conquered by the Ostrogothic Kingdom. Consequently, Rome's power declined, and it eventually became part of the Eastern Roman Empire, as the Duchy of Rome, from the 6th to 8th centuries. At this time, the city was reduced to a fraction of its former size, being sacked several times in the 5th to 6th centuries, even temporarily depopulated entirely.
• Medieval Rome is characterised by a break with Constantinople and the formation of the Papal States. The Papacy struggled to retain influence in the emerging Holy Roman Empire, and during the saeculum obscurum, the population of Rome fell to as low as 30,000 inhabitants. Following the East–West Schism and the limited success in the Investiture Controversy, the Papacy did gain considerable influence in the High Middle Ages, but with the Avignon Papacy and the Western Schism, the city of Rome was reduced to irrelevance, its population falling below 20,000. Rome's decline into complete irrelevance during the medieval period, with the associated lack of construction activity, assured the survival of very significant ancient Roman material remains in the centre of the city, some abandoned and others continuing in use.
• The Roman Renaissance occurred in the 15th century, when Rome replaced Florence as the centre of artistic and cultural influence. The Roman Renaissance was cut short abruptly with the devastation of the city in 1527, but the Papacy reasserted itself in the Counter-Reformation, and the city continued to flourish during the early modern period. Rome was annexed by Napoleon and was part of the First French Empire from 1809 to 1814.
• Modern history, the period from the 19th century to the present. Rome came under siege again after the Allied invasion of Italy and was bombed several times. It was declared an open city on 14 August 1943. Rome became the capital of the Italian Republic (established in 1946). With a population of 4.4 million (as of 2015; 2.9 million within city limits), it is the largest city in Italy. It is among the largest urban areas of the European Union and classified as a global city.