Adoption in ancient Rome

The Roman Republic was a form of government of Rome and the era of the classical Roman civilization when it was run through public representation of the Roman people. Beginning with the overthrow of the Roman Kingdom and ending in 27 BC with the establishment of the Roman Empire, Rome's control rapidly expanded during this period—from the city's immediate surroundings to hegemony over the entire Mediterranean world.

The Roman Empire was the post-Republican period of ancient Rome. As a polity, it included large territorial holdings around the Mediterranean Sea in Europe, North Africa, and Western Asia, and was ruled by emperors. From the accession of Caesar Augustus as the first Roman emperor to the military anarchy of the 3rd century, it was a Principate with Italia as the metropole of its provinces and the city of Rome as its sole capital. The Empire was later ruled by multiple emperors who shared control over the Western Roman Empire and the Eastern Roman Empire. The city of Rome remained the nominal capital of both parts until AD 476 when the imperial insignia were sent to Constantinople following the capture of the Western capital of Ravenna by the Germanic barbarians. The adoption of Christianity as the state church of the Roman Empire in AD 380 and the fall of the Western Roman Empire to Germanic kings conventionally marks the end of classical antiquity and the beginning of the Middle Ages. Because of these events, along with the gradual Hellenization of the Eastern Roman Empire, historians distinguish the medieval Roman Empire that remained in the Eastern provinces as the Byzantine Empire.

Caesar Augustus, also known as Octavian, was the first Roman emperor; he reigned from 27 BC until his death in AD 14. He is known for being the founder of the Roman Principate, which is the first phase of the Roman Empire, and is considered one of the greatest leaders in human history. The reign of Augustus initiated an imperial cult as well as an era associated with imperial peace, the Pax Romana or Pax Augusta. The Roman world was largely free from large-scale conflict for more than two centuries despite continuous wars of imperial expansion on the empire's frontiers and the year-long civil war known as the "Year of the Four Emperors" over the imperial succession.

Gaius Julius Caesar was a Roman general and statesman. A member of the First Triumvirate, Caesar led the Roman armies in the Gallic Wars before defeating his political rival Pompey in a civil war, and subsequently became dictator from 49 BC until his assassination in 44 BC. He played a critical role in the events that led to the demise of the Roman Republic and the rise of the Roman Empire.

Auctoritas is a Latin word which is the origin of English "authority". While historically its use in English was restricted to discussions of the political history of Rome, the beginning of phenomenological philosophy in the 20th century expanded the use of the word.

Gaius Caesar was the grandson and heir to the throne of Roman emperor Augustus, alongside his younger brother Lucius Caesar. Although he was born to Marcus Vipsanius Agrippa and Julia, Augustus' only daughter, Gaius and his younger brother, Lucius Caesar, were raised by their grandfather as his adopted sons and joint-heirs to the empire. He would experience an accelerated political career befitting a member of the Julio-Claudian dynasty, with the Roman Senate allowing him to advance his career without first holding a quaestorship or praetorship, offices that ordinary senators were required to hold as part of the cursus honorum.

Lucius Caesar was a grandson of Augustus, the first Roman emperor. The son of Marcus Vipsanius Agrippa and Julia the Elder, Augustus' only daughter, Lucius was adopted by his grandfather along with his older brother, Gaius Caesar. As the emperor's adopted sons and joint-heirs to the Roman Empire, Lucius and Gaius had promising political and military careers. However, Lucius died of a sudden illness on 20 August AD 2, in Massilia, Gaul, while traveling to meet the Roman army in Hispania. His brother Gaius also died at a relatively young age on 21 February, AD 4. The untimely loss of both heirs compelled Augustus to redraw the line of succession by adopting Lucius' younger brother, Agrippa Postumus as well as his stepson, Tiberius on 26 June AD 4.

Marcus Agrippa Postumus, later named Agrippa Julius Caesar, was a Roman nobleman who was the youngest son of Marcus Vipsanius Agrippa and Julia the Elder, the daughter and only biological child of the Roman Emperor Augustus. Augustus initially considered Postumus as a potential successor, and formally adopted him as his heir, but banished him from Rome in AD 6 on account of his ferocia. In effect, this action cancelled his adoption, and virtually assured Tiberius' emplacement as Augustus' sole heir. Postumus was ultimately executed by his own guards shortly after Augustus' death in AD 14.

Germanicus Julius Caesar was an ancient Roman general and politician most famously known for his campaigns in Germania. The son of Nero Claudius Drusus and Antonia the Younger, Germanicus was born into an influential branch of the patrician gens Claudia. The agnomen Germanicus was added to his full name in 9 BC when it was posthumously awarded to his father in honor of his victories in Germania. In AD 4 he was adopted by his paternal uncle Tiberius, who succeeded Augustus as Roman emperor a decade later. As a result, Germanicus became an official member of the gens Julia, another prominent family, to which he was related on his mother's side. His connection to the Julii Caesares was further consolidated through a marriage between himself and Agrippina the Elder, a granddaughter of Augustus. He was also the father of Caligula, the maternal grandfather of Nero, and the older brother of Claudius.

Caligula, formally known as Gaius, was the third Roman emperor, ruling from AD 37 until his assassination in AD 41. He was the son of the Roman general Germanicus and Agrippina the Elder, Augustus' granddaughter. Caligula was born into the first ruling family of the Roman Empire, conventionally known as the Julio-Claudian dynasty.

Tiberius Claudius Caesar Augustus Germanicus was the fourth Roman emperor, ruling from AD 41 to 54. A member of the Julio-Claudian dynasty, Claudius was born to Drusus and Antonia Minor at Lugdunum in Roman Gaul, where his father was stationed as a military legate. He was the first Roman emperor to be born outside Italy. Nonetheless, Claudius was an Italian of Sabine origins.

Nero Claudius Caesar Augustus Germanicus, was the fifth Roman emperor and final emperor of the Julio-Claudian dynasty, reigning from AD 54 until his death in AD 68. He was adopted by the Roman emperor Claudius at the age of 13 and succeeded him on the throne. Nero was popular with the members of his Praetorian Guard and lower-class commoners in Rome and its provinces, but he was deeply resented by the Roman aristocracy. Most contemporary sources describe him as tyrannical, self-indulgent, and debauched. After being declared a public enemy by the Roman Senate, he committed suicide at age 30.

Nerva was Roman emperor from 96 to 98. Nerva became emperor when aged almost 66, after a lifetime of imperial service under Nero and the succeeding rulers of the Flavian dynasty. Under Nero, he was a member of the imperial entourage and played a vital part in exposing the Pisonian conspiracy of 65. Later, as a loyalist to the Flavians, he attained consulships in 71 and 90 during the reigns of Vespasian and Domitian, respectively. On 18 September 96, Domitian was assassinated in a palace conspiracy involving members of the Praetorian Guard and several of his freedmen. On the same day, Nerva was declared emperor by the Roman Senate. As the new ruler of the Roman Empire, he vowed to restore liberties which had been curtailed during the autocratic government of Domitian.

Hadrian was Roman emperor from 117 to 138. He was born in Italica, a Roman municipium founded by Italic settlers in Hispania Baetica. He came from a branch of the gens Aelia that originated in the Picenean town of Hadria, the Aeli Hadriani. His father was of senatorial rank and was a first cousin of Emperor Trajan. Hadrian married Trajan's grand-niece Vibia Sabina early in his career before Trajan became emperor and possibly at the behest of Trajan's wife Pompeia Plotina. Plotina and Trajan's close friend and adviser Lucius Licinius Sura were well disposed towards Hadrian. When Trajan died, his widow claimed that he had nominated Hadrian as emperor immediately before his death.