[40] By the first century BC, Rome had grown so vast that its original government — a more democratic republic — had become unsuited to rule such a far-flung territory. That's when Rome went from republic to empire — from a focus on the collective good to the personal ambition of its ruler — and two dynamic men entered the scene…"Hail, Caesars."

[41] Julius Caesar and the next ruler, his great nephew who became the first emperor, Caesar Augustus, made sure the art of their time gave citizens confidence in their government. Portrait busts made it clear: looking into the eyes of the man who called himself "the first among equals," you're confident that the ship of state was in good hands.

[42, Pax Romana, 27 BC–AD 180] Augustus ushered in that 200 years of relative peace and prosperity known as the "Pax Romana," or Roman Peace. This glorious Altar of Peace embodies the dawning of that optimistic era.

[43, Ara Pacis (Altar of Peace), 9 BC, Rome] For the next two centuries, the vast Roman Empire — the entire Mediterranean world including much of Europe — enjoyed a Golden Age of good living and stability under Roman rule…at least according to the propaganda. These exquisite reliefs celebrate Rome's success and its prosperity. The goddess of fertility is surrounded by symbols of abundance. And the message is clear: we should be thankful for our emperor.

[44, Arch of Constantine, AD 312, Rome] It's a nice message, but the "peace" that altar celebrates came by oppressing and exploiting people in faraway lands. Throughout history, the victors get to shape their legacy through their art.

[26, High Corniche, near Nice, France] This modern cliff-hugging road in southern France actually sits upon an ancient highway built by the Romans as they consolidated their control of these hostile lands. And, declaring victory, stood an impressive use of art as propaganda:

[27, Trophy of the Alps, 6 BC, La Turbie (above Monaco), France] the towering "Trophy of the Alps" celebrates that conquest and the quelling of the last hostile tribe.

[28] With this victory, the completion of the main artery connecting Italy and Spain was made possible. This opened the way for the vast expansion of the Roman Empire.

[29] The inscription tells the story: it was erected "by the senate and the people" and lists all the feisty barbarian tribes that put up such a fight. The vanquished lie in chains at the feet of their conqueror — a stern reminder to any who would challenge the growing empire.

[45] The empire's great wealth — booty, taxes, and slave labor — flowed inward to the capital creating the greatest city ever seen, with a population of over a million.