2.1 After Mesopotamia — Two Millennia of Empire-Building

The two thousand years that followed the rise of Mesopotamian cities saw a long and unbroken series of attempts at empire-building^? across West Asia, the eastern Mediterranean and beyond. By the sixth century BCE, the Iranians^? had absorbed most of the old Assyrian heartland under the Achaemenid kings, and overland trade-routes meshed with the sea-lanes that ran along the coasts of the Mediterranean. Greek city-states such as Athens and Sparta — and their colonies on Sicily, in southern Italy and around the Black Sea — were drawn deeper into this widening commercial web, profiting also from contacts with the nomadic peoples of the Eurasian steppe.

From this Greek world emerged the campaigns of Alexander of Macedon^? in the late fourth century BCE. He overran parts of North Africa, West Asia and Iran and pushed eastwards as far as the river Beas in Punjab, where his exhausted soldiers refused to march further. Although his political empire fell apart soon after his death in 323 BCE, the cultural fusion he had set in motion did not. For roughly three centuries the eastern Mediterranean and West Asia became Hellenised^? — Greek language, philosophy and city-planning circulated alongside, and often within, older Iranian traditions which remained at least as influential.

2.2 The Rise of Rome — From Italian City-State to World Power

The political confusion that followed Alexander's death gave a small but well-disciplined central-Italian city-state its opportunity. From the second century BCE the armies of Rome^? moved methodically into North Africa and the eastern Mediterranean, defeating Carthage, the Macedonian successor kingdoms and the Seleucid heirs of Alexander. By around 31 BCE Rome controlled almost the entire Mediterranean rim.

At that time Rome was still officially a Republic^?. Its constitution combined elections, a powerful aristocratic council called the Senate^?, and popular assemblies, but birth and wealth carried great weight, and the entire economy rested on the labour of slaves. In the middle of the first century BCE, the high-born general Julius Caesar dragged Roman power across the Alps, conquering Gaul and probing Britain and Germany. His assassination in 44 BCE sparked a civil war that would, by 27 BCE, replace the Republic with a single-ruler regime under his adopted son Octavian — better known as Augustus^?.

2.2.1 The Two Halves of Roman History

It is convenient to split Roman political history into two great phases:

2.3 Sources — How Do We Know All This?

Romans bequeathed an unusually rich body of evidence. Three categories matter most:

2.4 The Three Players of Imperial Power

Throughout most of the Early Empire, real political authority rested on the interaction of three institutions. The historian Fergus Millar called them the "three players" of the Roman state.

An emperor could not rule without keeping all three roughly in balance. He was officially named by the Senate, but his real power flowed from the obedience of the legions on the frontier. As Tacitus shrewdly observed at the outset of his Histories, the civil wars of 69 CE — the Year of the Four Emperors — had revealed a "secret of empire" that "an emperor could be made elsewhere than at Rome", that is, in the camps of the legions on the Rhine, the Danube or the Euphrates.

2.4.1 The Senate Under the Emperors

The Senate had run the Republic. Under the emperors it lost most of its decisive role but kept its prestige. Senators continued to govern the older provinces such as Asia and Africa Proconsularis, to command legions, and to compete for the consulship — the highest of the old Republican offices, now mostly an honour. Tense relations between Senate and emperor are the great subject of the Annals: bad emperors (Tiberius, Caligula, Nero, Domitian) were remembered in senatorial historiography for executing senators, while good emperors (Augustus, Trajan, Marcus Aurelius) are praised for treating the Senate "with due respect".

2.4.2 The Roman Army

Unlike Iran's part-time levies or Greek citizen-militias, Rome's was a paid, professional, long-service army. A legionary served roughly 20 years, swore an annual oath of loyalty (sacramentum) to the emperor, and at retirement received a substantial cash bonus or a plot of frontier land. Auxiliary units, recruited from non-citizens of the provinces, served 25 years and earned Roman citizenship at discharge — a powerful incentive for cultural and political assimilation.

2.5 The Provinces — Empire as a Network of Cities

The Roman Empire was, more than anything else, an empire of cities. Each province^? was administered through a network of towns, each with its own council (curia) of local notables (decurions), its forum, basilica, baths and amphitheatre. By collecting taxes, supervising markets, repairing roads and providing recruits, these cities relieved the central government of work it could not have performed itself with so few officials.

The cities also provided the empire's elite. From the late first century CE, emperors increasingly came from the provinces: Trajan and Hadrian from Spain, Septimius Severus from Lepcis Magna in North Africa, the Severan dynasty's women from Syria, Diocletian from the Balkans. The "Romanness" of the empire became, in practice, a Mediterranean, three-continent identity rather than an Italian one.

2.6 The Augustan Settlement — How a Republic Became an Empire

In 31 BCE Octavian defeated his rival Mark Antony and Antony's ally, the last Hellenistic ruler of Egypt, Cleopatra VII. Egypt was annexed and added to the personal estate of the new ruler. Four years later, in 27 BCE, the Senate granted Octavian the honorific title Augustus ("the revered one") and a bundle of Republican powers — tribunician authority, proconsular command of the frontier provinces, and the title princeps ("first citizen"). The constitutional fiction held that the Republic had been "restored". The reality was a monarchy.

Augustus' settlement lasted, in essentials, for nearly three hundred years. Its four key features were:

• A standing professional army paid from a special military treasury (aerarium militare), founded in 6 CE.
• Direct rule of frontier provinces through legates appointed by the emperor; senatorial governors retained the older, peaceful provinces.
• An imperial cult that worshipped the emperor's genius (in Italy) or his person directly (in the Greek east), binding distant provincials to the regime.
• A massive building programme that turned Rome from a city of brick into a city of marble, while colonies and aqueducts spread Roman urban culture across the provinces.

2.7 An Empire of Many Peoples — Scale and Diversity

At its peak under Trajan, the Roman Empire enclosed perhaps 60 million people — roughly a quarter of the world's population at the time. It was multi-ethnic and multi-lingual. Latin dominated the western provinces (Spain, Gaul, North Africa west of Egypt, and the Latin parts of the Balkans). Greek prevailed in the eastern provinces (Greece, Asia Minor, Syria, Egypt). Aramaic, Coptic, Punic, Berber, Celtic and Germanic dialects survived as everyday speech beneath the imperial languages.

This diversity was held together by three Roman achievements: a uniform legal order (Roman civil law), a single high-quality silver and gold coinage, and a road system of more than 80,000 km that radiated from Rome to the most distant garrisons. The army's protection of these roads is what made long-distance trade — the subject of the next part of this chapter — economically possible.