Rome's rise and fall was like a human weather system, as destructive as nature's most violent hurricanes. This enormous whirlwind was powered by three essential ingredients: grain, booty and slaves.
Its internal momentum, sustained by violence, was hell-bent on keeping a rich ruling class in a lifestyle of luxury. Once the storm was over the landscape of Europe looked quite different, while the legacy of what made the ferocious ancient Roman Empire so powerful helped shape the rest of European history to come.
Roman legends give a clue as to what made these people tick because there is so much similarity between them and the mythological tales from Greece. The Romans were brilliant copycats. Infantry tactics, mythology, art and architecture came from Greece while their heavy cavalry and expertise in horses came from Persia. When the Romans wanted to attack the most powerful maritime city in the region, the Phoenicians' Carthage, they simply captured one of its ships and within the space of about two months built themselves from scratch an entire fleet of more than 100 similar ships.
An early threat to the rise of Rome came in the form of a famous Carthaginian general called Hannibal, who in 218BCE marched an army of mercenary soldiers and African war elephants all the way up Spain and across the Alps. His surprise attack from the north led to several victories, the most famous being at the Battle of Cannae (216BCE), near Apulia in south-east Italy, where Hannibal's cavalry encircled the massed ranks of Roman infantry, cutting them to pieces.
In the end, though, Roman persistence paid off. Knowing that Hannibal didn't have equipment such as siege engines needed to breach the walls of the city of Rome itself, the Roman forces just waited, shadowing his armies, watching his tactics, but always avoiding war. Meanwhile, another Roman army, under the leadership of a young commander, Scipio, defeated the Carthaginian forces in Spain and crossed the short stretch of sea to Africa where they marched towards Carthage itself. Hannibal had no choice but to return home to try to save his own city, but there he was defeated at the Battle of Zama in 202BCE.
By this time the Romans had become a highly efficient war machine, expanding their frontiers all around the Mediterranean and adapting their tactics to incorporate cavalry and ships. With each conquest they brought home huge hoards of booty in the form of treasure and prisoners-of-war whom they turned into slaves.
Plunder paid for a fabulously rich lifestyle for Rome's citizens, while imported slaves provided free labour in their homes, on the farms, in the city streets and on the many enormous construction projects that quickly turned Rome into the most advanced artificial world on Earth.
By 146BCE, a succession of military victories brought Greece into the Roman Empire, followed in 129BCE by Asia Minor. From here the Romans had the perfect bridgehead to launch a series of campaigns in the Near East, conquering Armenia, Lebanon, Syria and Judaea by 64BCE under the leadership of the general Pompey, each time adding further riches to their economy in the form of gold, silver and slaves.
To the south the Roman general Octavian, who later became the Emperor Caesar Augustus, added the jewel in the crown: the conquest of Egypt in 30BCE. With its almost limitless supplies of grain from the Nile Valley, the Egyptian bread basket provided the perfect finishing touch, supplying unlimited quantities of food throughout the Roman Empire.
But at the centre of the Roman grip on power lay an intractable problem. What does a civilisation that is built on military conquest and financial growth do when it finds that, for various reasons, it cannot expand any more? Gaul (modern-day France) had been brought under Roman control by Julius Caesar in 46BCE and Britain was finally subjugated after the failed revolt of Boudicca at the Battle of Watling Street in 61CE. But further expansion towards Scotland proved profitless and eventually the Romans built a wall to keep out the violent Picts.
In the north-east, the Romans were forced to post several legions along the natural border of the Rhine and Danube rivers in an effort to contain Germanic tribes such as the Goths and Visigoths, who they found impossible to bring under control, despite numerous attempts. To the east a new Persian Empire had overthrown the Greek generals put in place by Alexander. Their Azatan knights successfully held the Romans back from the rich lands of the Middle East. Then there were nature's barriers. To the West, after Spain, there was the edge of the world – the apparently endless Atlantic Ocean. To the south, beyond Carthage and Egypt, there was just dry, barren, lifeless desert.
Somehow, against all odds, Roman civilisation survived for hundreds of years even after further expansion had become impossible. The story of the later Roman Empire is the tale of how a human civilisation, fixed on violence and growth, managed to hold itself together despite reaching expansion's elastic limit. Thanks to a variety of ingenious and often brutal strategies the ruling Roman oligarchy was able to sustain its luxurious standard of living for an impressive 300 years after the major phase of expansion ended.
Imperial Rome's first survival tactic was political. Tyrannical rule was necessary to force through a rapid succession of reforms needed to hold this violent land and sea-locked society together. At least 40 per cent of the capital city's massive population were slaves. They made a doomed attempt at breaking the grip of imperial and dictatorial government when a leader called Spartacus, an escaped Greek gladiator, rallied them to rebellion in 79BCE. After some initial successes they were eventually routed by the Roman general Marcus Crassus in southern Italy. More than 6,000 were crucified, their crosses set up along the 130km stretch of road from Capua to Rome. Crassus ordered that their bodies never be removed. There they remained as rotten carcasses for many years, a gruesome memorial of what happened to slaves who disobeyed their masters.
Other strategies were also deployed by Roman rulers to keep the huge population of their capital city under firm control. One tactic was to divert the poor and enslaved into building projects to provide improved amenities for the well-off. With this policy the Roman Empire rapidly became the fountain from which mammoth engineering works were undertaken all over its conquered lands. Many of their ruins survive today across Europe, North Africa and the Near East.
Exploiting labour from slaves and the poor gave birth to Europe's first comprehensive road network – essential infrastructure for keeping order and control in an empire that at its biggest, in about 100CE, covered over 5 million square kilometres. Slaves, supervised by soldiers, built more than 85,000km of road, most of them in straight lines, making man's first long cuts of bricks, cement and concrete into Europe's supple surfaces. Everything that got in the way, from forests to farms, was razed to the ground.
Spectacular forms of mass-market entertainment were another part of the system for keeping the overpopulated Roman capital governable. Riches won after suppressing a Jewish revolt against Roman rule that began in 66CE financed the cost of building Rome's giant Flavian amphitheatre (the Colosseum), which was constructed under the Emperor Vespasian.
When it was opened in 80CE, this theatre could seat more than 50,000 spectators, comparable to many large modern sports stadiums. A new emperor, Titus, celebrated the opening of this temple to entertainment by giving the people of Rome 100 days of spectacular drama in the form of mock battles, gladiator fights, animal hunts and executions. According to the contemporary historian Dio Cassius, more than 11,000 wild animals were killed in these games. Several of them, such as lions, crocodiles, elephants, giraffes, panthers, leopards, hippos, rhinos and ostriches, had been imported from across the empire. Attendance was free. The Emperor came to the games so his people could admire him in all his glory. He was only too happy to see the most violent of the Roman underclass gratified and in one location, safe under the watchful eye of the imperial guard.