Jus trium liberorum
The jus trium liberorum (Latin, "the right of three children"; also spelled ius), was a privilege awarded to Roman citizens who had produced at least three children or to freedpersons who had produced at least four. The privilege resulted from the Lex Papia Poppaea and other legislation on morality introduced by Augustus in the first centuries BC and AD. These laws were intended to increase the dwindling population of the Roman upper classes.