Titus Livius (59BC-AD17) began working on his History of Rome at the age of 30 and continued for over 40 years until his death. The history ran to 142 books, of which 35 survive.
Livy's brilliant history of the founding and early years of Rome
The fourth volume of Livy's history of the Roman Empire
If you're spending all your waking time thinking about the Roman Empire (as many of us are), why not read about it too?