Adoption in the Roman Empire

What do Augustus, Tiberius, and Marcus Aurelius,
three of the greatest Roman emperors,
have in common?

Adopted Emperors

Augustus (Gaius Julius Caesar Octavianus), Tiberius Julius Caesar, and Marcus Aurelius

The motivation to adopt was very different in Roman times than today. While contemporary adoption is aimed at placing a child in a loving family, Roman adoption aimed at providing a suitable male heir to become the new pater familias when the family patriarch died. If a man had no sons, adoption was a common solution among the noble orders of senators and equestrians. How common it was among the lower classes is harder to determine. Women were seldom adopted, regardless of class.

Families with surplus sons were often willing to have one or more sons adopted to make desirable family connections and to improve their sons’ opportunities. The adopted son was usually an older son who had survived childhood and displayed desirable traits as an adult. Since a minimum net worth was required to remain in the noble orders (1,000,000 sesterces for senators and 400,000 sesterces for equestrians), a noble family of moderate means might not be rich enough upon the death of the father to provide all the sons with enough to stay above the minimum. Adoption into another noble family simultaneously solved the problems of no heir for one and too many heirs for the other.

Adoptions of men in their twenties and thirties to increase opportunities based on money or political connections were fairly common, and there was no social stigma involved for either family. It wasn’t even necessary for the person being adopted to be younger than the person doing the adopting.

Roman adoption laws
The following discussion concerns adoption of one Roman citizen by another. Under Roman law, a free non-citizen (peregrine) could not be adopted by a citizen. A slave could be freed to become a Roman citizen; the freedman, who was now a Roman citizen, could then be adopted.

In the Roman system, the transfer of a son from one family to another fell into two different categories: 1) the man or boy being adopted was alieni iuris, that is, still under the control of a pater familias, the patriarch or head of a family, or 2) he had become the head of the family himself (sui iuris) by the death of the former patriarch.

In the first case, the son who is not his own master (alieni iuris) switched from the control of his own pater familias to the control of his adoptive pater familias. This process was called adoption. Since the one being adopted owned no property (it all belonged to the pater famlias), he brought no property with him. If he was older and had children, he left those behind in his original family.

In the second case, the man who was sui iuris could be a pater familias himself, even if he was still a child. When he was adopted, he brought all his property and any descendents with him into the new family. This process was called adrogation. Because his former family essentially ceased to exist when he became a member of the new family, public permission was required for adrogation.

Females were seldom adopted. The purpose of adoption of either type was to ensure continuity in the patriarchal authority (patria potestas) of a family. Since females had no patriarchal authority, they could neither adopt nor adrogate. Since they were under the control of a family patriarch, they were not sui iuris and could not be adrogated. They could be adopted, although this was uncommon.

Adoption as a way to make natural children legitimate
If a citizen had natural children by a woman other than his legally recognized wife, he could make the boys legitimate by adrogation. If they were already free, he could simply adrogate. If they were slave, he could free them, making them citizens, and then adrogate. If the boy was not a citizen, he could not be adrogated or adopted. Citizen or not, girls could not be adrogated; so their father couldn’t make his natural daughters legitimate.

How Judah ben Hur could become the son of Quintus Arrius
In Lew Wallace’s novel, Ben Hur: A Tale of the Christ, Judah ben Hur is adopted by the Roman admiral, Quintus Arrius, after saving him from drowning. If Judah was a free man, Arrius could not adopt him since he was not a Roman citizen. If he was a slave, Arrius could buy him. Then he could free him, making Judah a citizen. Once Judah was a citizen, Arrius could adrogate him. Judah would then take the name of his new father, becoming Quintus Arrius.

Name changes when adopted or adrogated
The name of a male Roman citizen had three parts: praenomen (given name), nomen (clan or gens), and cognomen (family name). It was customary for an adopted male to replace his original clan and family names with those of his adoptive father. His original clan name was added after the cognomen with the –us ending changed to –anus. For example, if Gaius Cornelius Lentulus was adopted by Titus Livius Drusus, he would become Gaius Livius Drusus Cornelianus.

Famous Adopted Romans
One of the best known adoptees during the Republic was Publius Cornelius Scipio Aemilianus, commander of the Roman army in the Third Punic War, when Carthage was destroyed in 146 BC. His birth father was Lucius Aemilius Paullus, hence the fourth name Aemilianus. His adoptive grandfather was Publius Cornelius Scipio Africanus Maior, who defeated Hannibal at the battle of Zama in 202 BC to end the Second Punic War.

The most famous adoptees of the imperial period were adopted by emperors to provide a male heir, who then became the next emperor.

Augustus bust

Augustus (Gaius Julius Caesar Octavianus)

Augustus Caesar was born Gaius Octavius Thurinus. He was the great-nephew of Gaius Julius Caesar. In his will, Julius Caesar adopted Octavius, making him Gaius Julius Caesar Octavianus. He was 18 at the time.

In turn, Augustus solved the problem of succession by adoption. When he married Livia Drusilla after her divorce from Tiberius Claudius Nero, her son, also named Tiberius Claudius Nero, became Octavian’s stepson. (This was in 38 BC, before Octavian was given the title Augustus in 27 BC.) Many years later, after Augustus’s grandsons had died, he formally adopted Tiberius to make him Tiberius Julius Caesar Claudianus, although the Claudianus is normally omitted. As his son and only male heir, Tiberius would become the next emperor (officially the next princeps civitatis (first citizen), but an emperor by any other name is still an emperor). The Julio-Claudian dynastic name reflects Tiberius’s adopted status.

During the first 200 years of the Empire, adoption became a common practice when the emperor had no suitable son to succeed him. An emperor approaching the end of his life adopted a man whom he expected would rule well. This pattern was initiated by Nerva and continued by Trajan, Hadrian, Antonius Pius, and Marcus Aurelius. It is not surprising that these men, who were selected based on merit instead of bloodline, are regarded as four of the best emperors.


Adkins, Lesley and Roy A. Adkins. Handbook to Life in Ancient Rome. New York: Oxford University Press, 1998.

Crook, J. A. Law and Life of Rome, 90 BC. ― A.D. 212. Ithaca, NY: Cornell University Press, 1967.

Busts of Augustus, Tiberius, and Marcus Aurelius are at the Walters Art Museum, Baltimore, MD


Fact and Fiction by Carol Ashby