Adoption in ancient Rome was primarily a legal procedure for transferring paternal power (potestas) to ensure succession in the male line within Roman patriarchal society. The Latin word adoptio refers broadly to "adoption", which was of two kinds: the transferral of potestas over a free person from one head of household to another; and adrogatio, when the adoptee had been acting sui iuris as a legal adult but assumed the status of unemancipated son for purposes of inheritance. Adoptio was a longstanding part of Roman family law pertaining to paternal responsibilities such as perpetuating the value of the family estate and ancestral rites (sacra), which were concerns of the Roman property-owning classes and cultural elite. During the Principate, adoption became a way to ensure imperial succession.
In contrast to modern adoption, Roman adoptio was neither designed nor intended to build emotionally satisfying families and support childrearing. Among all social classes, childless couples or those who wanted to expand the size of their families instead might foster children. Evidence is meager for the adoptio of young children for purposes other than securing a male heir, and probably would have been employed mostly by former slaves legitimating the status of their own children born into slavery or outside a legally valid marriage.
