Titus Livius Patavinus (59 BCE – CE 17) — known as Livy in English — is a Roman historian who writes a monumental history of Rome and the Roman people.

Ab Urbe Condita Libri, "Books from the Foundation of the City," covering the period from the earliest legends of Rome well before the traditional foundation in 753 BCE through the reign of Augustus in Livy's own time.

He is on familiar terms with the Julio-Claudian family, advising Augustus's grandnephew, the future emperor Claudius, as a young man not long before CE 14 in a letter to take up the writing of history.

Livy and Augustus's wife, Livia, are from the same clan in different locations, although not related by blood.