- The Decline and Fall of the Roman Empire by Edward Gibbon. (Also available on audio and MP3 format.): http://smile.amazon.com/Decline-Fall-Roman-Empire-Everymans/dp/0679423087
- John Julius Norwich wrote a good 3-volume history of the Byzantine Empire, also known as the Eastern Roman Empire: http://smile.amazon.com/Byzantium-Centuries-John-Julius-Norwich/dp/0394537785
- Constantine the Great was very important to the development of Christianity.
- *Rubicon: The Last Years of the Roman Republic by Tom Holland. Also his book on Persia – Persian Fire: The First World Empire and the Battle for the West are alright. (Both are also available on audio and MP3 format.): http://smile.amazon.com/Rubicon-Last-Years-Roman-Republic/dp/038550313X, http://smile.amazon.com/Persian-Fire-First-Empire-Battle/dp/0385513119.
- Cicero: The Life and Times of Rome’s Greatest Politician by Anthony Everitt. (Also available on audio format.) Good piece at Salon about this book: http://smile.amazon.com/Cicero-Times-Romes-Greatest-Politician/dp/037575895X/, http://dir.salon.com/story/books/feature/2002/08/27/cicero/index.html
- Augustus: The Life of Rome’s First Emperor also by Anthony Everitt. (Available on audio and CD format.): http://smile.amazon.com/Augustus-Life-Romes-First-Emperor/dp/1400061288
- The Roman Emperors: A Biographical Guide to the Rulers of Imperial Rome 318 B.C. – A.D. 476 by Michael Grant: http://smile.amazon.com/The-Roman-Emperors-Biographical-Imperial/dp/0760700915
- *SPQR: A History of Ancient Rome by Mary Beard: http://smile.amazon.com/SPQR-A-History-Ancient-Rome/dp/0871404230