What if Hannibal had marched on Rome?

[Please consider purchasing Impossible Histories , the book that is just like this essay except better researched, or pre-ordering Apprentice Academy : Sorcerers , a book unlike this essay in every way.]

Why, let us build a city of our own,
And not stand lingering here for amorous looks.
•Marlowe, Dido, Queen of Carthage (c. 1586?).

The Roman historian Livy (59 BC–17 AD) wanted nothing so much as to explain to his readers what made Romans so impressively powerful, virtuous, etc. and look! now they have...