5 Ancient Battles That Ended Empires

5 The Battle Of Mobei
119 BC

The Battle of Mobei (or the Battle of the Northern Desert) was a hard-fought military campaign led by the Han Dynasty against the Xiongnu, a nomadic tribe. The Xiongnu were barbarians to the Han, who had maintained a contentious relationship over the years due to the security of their northern borders. Xiongnu strength had increased following the fall of Qin and the Chinese Civil War, but the Han launched an offensive to challenge their strength.
A force of 300,000 men and 140,000 horses attacked a much smaller Xiongu force of 100,000 soldiers and 80,000 horses. The victory was decisive for the Han, but they suffered the loss of most of their horses, which took a toll on their economy.
The Xiongnu suffered a much greater loss and were never able to recover from their defeat. Within a few years, the Xiongnu would be nothing more than a small group of clans.

4 The Siege Of Alesia
52 BC

By September 52 BC, the forces of Julius Caesar were facing a confederation of Gallic tribes commanded by Vercingetorix. In the final engagement between Rome and Gaul, Caesar conducted one of the most tactful sieges in history. With a force of 12 legions (approximately 60,000 men) and 120,000 Gaul allied-auxiliaries, Caesar besieged a Gallic force nearly four times the size of his.
The battle itself is considered to be one of Caesar’s greatest military achievements due to his use of a circumvallation around Alesia. He ordered the construction of numerous, heavily fortified forts to encircle and blockade the city so that he could “starve out” the Gallic forces. His investment paid off, as the Gauls failed to break the Roman defenses despite numerous attempts, further weakening themselves. By the end of the battle, Vercingetorix was surrendered to Caesar. The Siege of Alesia ended Gallic independence from Rome and won a substantial victory for Caesar.

3 The Battle Of Philippi
42 BC

Caesar’s conquest of Gaul created a political crisis in Rome, which lead to civil war. He was soon assassinated by members of the Roman Senate, which sparked a second civil war declared by the Second Triumvirate of Mark Antony and Octavian. The forces of Brutus and Cassius fought their final battle against the Triumvirate at Philippi in 42 BC.
The battle was split into two fronts, which saw Antony face Cassius and Octavian against Brutus. Antony made short work of Cassius and defeated much of his army. Cassius committed suicide on the false report that Brutus’ forces were likewise destroyed, even as those men were forcing their way into Octavian’s legions’ camps. Antony joined Octavian, and the two overwhelmed Brutus, who committed suicide in defeat.
With the last remnants of the old Republic destroyed, the Triumvirate took control of Rome, which soon became a new empire under Caesar Augustus (Octavian).

2 The Battle Of Teutoburg Forest
AD 9

If the Roman Republic and Empire were known for anything, it was their rapid and continuous expansion throughout Europe and Asia. It took mighty armies of unregulated barbarian tribes to put much of this expansion to a final halt in AD 9, after the Battle of Teutoburg Forest. The battle was the result of an ambush made by an alliance of Germanic tribes, who attacked and completely destroyed three Roman legions and their auxiliaries.
The blow was devastating to Roman morale, and despite several successful incursions in the following years, Rome never again attempted to defeat the Germanic tribes north of the Rhine. The Battle of Teutoburg Forest is remembered as one of the worst defeats in Roman history as well as a turning point in their military strategy of northward expansion.

1 The Battle Of Edessa
AD 260

Roman and Persian forces clashed in a devastating defeat for the Romans at the Battle of Edessa in AD 260. Under the command of Emperor Valerian, the Roman Army of 70,000 men attacked the Sassanid forces under the command of Shapur I, king of the kings. The entirety of the Roman army was defeated and captured, including Emperor Valerian—the first time such an event had occurred in Roman history.
Rome never fully recovered from their defeat at Edessa, which had long-lasting impacts on the political climate of the empire. The defeat was one in a long series of crises that afflicted Rome during the third century, which ultimately led to the creation of the Western Roman Empire in 285. Eventually, the Western Roman Empire fell, and Rome continued weakly into the fifth century after the Eastern Roman Empire (aka theByzantine Empire) rose to power in 330.