When the catapult was invented, the Western Greek world was still in the era of the city-state. A city-state was a single-city kingdom that had influence over its surrounding territory. It had its own religion, politics, and army, and indeed to the Greeks politics was religion. Participating in the city’s political affairs was only granted to citizens. Political participation was seen as a religious duty.
Athens had desired to transcend its status as a mere city-state and expand into an empire, but it got into a war with Sparta from 431 BC to 404 BC, called the Peloponnesian War, and lost. The war all but ruined Athens. Nevertheless, undeterred by the ruination of Athens, other city-states in the area desired greater power, too. One of them was Carthage, a city-state located on the northern coast of Africa. It wanted to take over the island of Sicily and the cities there, including Syracuse.
Carthage attacked Syracuse around 406 BC, but its invasion was held back by the Greek tyrant who ruled the city, Dionysius I. Carthage brought various siege engines to battle against Syracuse, including battering rams and siege towers. They were required because Syracuse was surrounded by walls, and Carthage was trying to bring those walls down.
It failed, and Dionysius ended up striking a peace treaty with Carthage in 405 BC. But Dionysius didn’t plan to stay at peace. He used the peace treaty to his benefit to gather his army’s strength. He prepared an invasion against the center of Carthaginian influence in the area, the city of Motya, in 397 BC.
Now, Motya was unique because it was an island city enclosed by walls. It was well protected and hard to attack. But Dionysius had gained insight from the Carthaginian siege machines and used it to overcome this problem. He combined the large scale and power of the siege machines with the gastraphetes, an early crossbow used by the Greeks at the time, creating the ballista, or catapult.
Carthage sent a fleet of ships to help defend the city and deflect the assault by Dionysius. However, Dionysius used the catapult to defeat Carthage’s naval force by firing missiles at them from the shore. Caught off guard and totally surprised by this new development, Carthage was incapable of defending against the new device. Carthage abandoned the battle and sailed home, leaving Motya to be captured by Dionysius.
The catapult created new military tactics. It opened up new offensive and defensive strategies. Not just heavy projectiles, but fire bombs and even dead bodies could be hurled over city walls to help destroy the enemy from within by demoralizing the citizens and the soldiers. Alternatively, the catapult could be mounted inside city walls to rain down defensive artillery onto invading armies.
Though it was Dionysius who was one of the first to build a catapult around 400 BC, it wasn’t until Alexander the Great put it to use and improved it with innovations like the torsion spring that it became a significant military staple.
Alexander put it to creative use, particularly in his battle against Tyre, which was another fortified island city like Motya. He even mounted the catapult to his ships so that he could sail them into position as needed to get a better shot. He used the catapult to help build his empire, and after his death his empire was split up and placed into the hands of multiple leaders. They also gained access to his military equipment.
Consequently, the catapult signaled that a new period in history was coming. With it, Alexander was able to unify practically the entire world into a great empire, the first time such a thing had been accomplished. This spread Hellenstic culture far and wide, which gave birth to a new period of technological creativity.
This legacy would eventually be inherited by the Roman Empire, at least most of it. They used and improved the catapult, and it became an important part of the military tactics which they used to conquer as much of the world as they did.
The Babylonian empire had come to an end in 539 BC with the rise of the Medo-Persian empire. The Medo-Persian empire, after tangling with the Greek city-states for a while, came to an end in 330 BC. In the aftermath of the Peloponnesian War, and resenting Spartan rule, the Macedonian empire rose up under the leadership of Alexander the Great. This gave way to the Roman Empire.
These events were spoken of by Daniel to King Nebuchadnezzar hundreds of years earlier:
Another kingdom inferior to you shall arise after you, and yet a third kingdom vof bronze, which shall rule over all the earth. And there shall be a fourth kingdom, strong as iron, because iron breaks to pieces and shatters all things. And like iron that crushes, it shall break and crush all these. (Daniel 2:39-40)
The Roman Empire collapsed in 476 AD. The Eastern Empire remained united for another thousand years, but the Western empire fractured. Out of Western Rome’s collapse grew the decentralized feudal order of the Middle Ages which, while greatly splintered, was increasingly unified not by a common government, but by a common worldview: Christianity.