Ancient Rome had conquered the world three times: first through its armies, then through its religion, finally through its laws.

German legal theorist Rudolf von Jhering famously remarked that ancient Rome had conquered the world three times: the first time through its armies, the second through its religion, the third through its laws. He might have added: each time more thoroughly.

The Empire, after all, only spanned a tiny portion of the globe; the Roman Catholic Church has spread farther; Roman law has come to provide the language and conceptual underpinnings of legal and constitutional orders everywhere.

Law students from South Africa to Peru are expected to spend a good deal of their time memorizing technical terms in Latin, and it is Roman law that provides almost all our basic conceptions about contract, obligation, torts, property, and jurisdiction—and, in a broader sense, of citizenship, rights, and liberties on which political life, too, is based.