The Roman Empire

The Roman Empire at its territorial peak under Trajan encompassed some 5 million square kilometers and perhaps 70 million people — roughly one-quarter of the world's population. From Britain to Mesopotamia, from the Rhine to the Sahara, this vast realm was connected by a network of roads, a common legal system, and the Latin language that would shape European civilization long after the empire itself had fallen.

The empire emerged from the ruins of the Republic when Octavian — later Augustus — defeated his rivals and established a new political order. The Principate, as this system is called, maintained the forms of republican government while concentrating real power in the hands of the emperor. Augustus' genius was making autocracy palatable by disguising it as the restoration of traditional values.

The Pax Romana that followed Augustus' settlement — roughly two centuries of relative peace and stability — was one of the most remarkable periods in world history. Trade flourished across the Mediterranean. Cities grew and prospered. Roman engineering produced roads, aqueducts, amphitheaters, and public baths that still inspire awe. But the empire also rested on slavery, military conquest, and the ruthless suppression of dissent. Its legacy, like its history, is profoundly complex.