A native of Padua on the Po River in northern Italy, Titus Livius (around 59 BC - AD 17), in English known as Livy, wrote a monumental history of Rome from its founding in 753 BC. The book's title, Ab Urbe Condita ("From the Founding of the City"), makes Livy's ambition clear, but not his method. He writes in a mixture of annual chronology and narrative - often having to interrupt a story to announce the elections of new Consuls at Rome. Livy's task was made the more difficult because of a lack of historical data prior to the sacking of Rome in 390 BC by the Gauls.
Livy wrote the majority of his works under Augustus, but is often identified with an attachment to the Roman Republic and a desire for its restoration. Since we lack the later books discussing the end of the Republic and the rise of Augustus, this is a moot point. Certainly Livy questioned some of the values of the new regime but it is likely that his position was more complex than a simple 'republic/empire' preference.