The First Man in Rome (Masters of Rome #1) by Colleen McCullough

From the bestselling author of The Thorn Birds comes a masterpiece of historical fiction that is fascinating, moving, and gloriously heroic. The reader is swept into the whirlpool of pageantry, passion, splendor, chaos and earth-shattering upheaval that was ancient Rome. Here is the story of Marius, wealthy but lowborn, and Sulla, aristocratic but penniless and debauched -- extraordinary men of vision whose ruthless ambition will lay the foundations of the most awesome and enduring empire known to humankind.