The Epic Legacy of Alexander the Great: 10 Defining Achievements

Alexander the Great, born in 356 BCE in the city of Pella, Central Macedonia, was the son of King Philip II and his fourth wife, Olympias. Widely regarded as one of history’s most brilliant military minds and charismatic leaders, Alexander earned his legendary title “the Great” through a stunning campaign of conquest that reshaped the ancient world.

By the time of his death at just 32, Alexander’s empire stretched over 5.2 million square kilometers, making it the largest in the world at the time. His military campaigns didn’t just conquer land—they connected East and West, laying the groundwork for centuries of cultural exchange.

Let’s explore the 10 most iconic achievements of Alexander’s remarkable military career.

The Battle of Chaeronea: A Young Commander Emerges

At just 18 years old, Alexander took command of the left wing of the Macedonian army during the Battle of Chaeronea in 338 BCE. This pivotal clash was against a coalition of Greek city-states, including Athens and Thebes, who feared Macedonian dominance.

Alexander led a decisive cavalry charge that shattered the elite Sacred Band of Thebes, once considered unbeatable. This victory cemented Macedonian supremacy in Greece—and marked the young prince as a prodigious military talent.

A King at 20: Securing Power After Philip’s Assassination

Following the assassination of Philip II in 336 BCE, the 20-year-old Alexander ascended to the throne. His rise sparked rebellions in key regions like Thessaly, Athens, and Thebes.

Alexander acted quickly, marching south with 3,000 cavalry. He crushed the resistance, forced Athens into submission, and was named hegemon of the Hellenic League at Corinth—a unified Greek force that he would soon lead against Persia.

Total Control of Greece: Suppressing Rebellions

Before turning eastward, Alexander needed to secure his northern borders. He launched campaigns against Thracian tribes, Illyrian kings, and the rebellious city of Thebes.

After Thebes revolted again, Alexander razed the city, sending a clear message to all of Greece. Within just two years of becoming king, Alexander had unified Greece and was ready to take on the might of Persia.

Conquering the Persian Empire: A Masterclass in Strategy

The Achaemenid Empire, founded by Cyrus the Great, was one of the most powerful empires in history. As Alexander crossed into Asia Minor, he encountered a Persian coalition at the Battle of the Granicus River.

Despite being outnumbered, Alexander neutralized the Persians’ advantage by fighting along the muddy riverbanks, where their deadly chariots were ineffective. He led a wedge-shaped cavalry assault that broke through the enemy lines, killing several high-ranking Persian nobles in hand-to-hand combat. The victory opened the door to further conquests across Asia Minor.

The Battle of Issus: Breaking Persian Momentum

After Granicus, Persian King Darius III regrouped and personally led a vast army to cut off Alexander’s supply lines near the town of Issus.

Despite being in a tight mountain pass, Alexander used clever tactics to force Darius into retreat. A daring cavalry assault on the Persian left flank caused chaos, and Alexander nearly captured Darius himself. The Battle of Issus marked a critical turning point in the campaign against Persia.

The Fall of Tyre and Gaza: Securing the Supply Chain

Before moving inland, Alexander needed control over the eastern Mediterranean coast. The island city of Tyre, a Phoenician stronghold, refused to surrender. Undeterred, Alexander began a seven-month siege, building a causeway to reach the island and deploying massive siege towers.

Once Tyre fell, Alexander marched south to Gaza, which also resisted fiercely. After a bloody siege, Gaza was captured, opening the road to Egypt—where Alexander would be welcomed not as a conqueror, but as a liberator.

The Battle of Gaugamela: The Decisive Blow

In 331 BCE, Alexander faced Darius III again at Gaugamela—modern-day Kurdistan. This time, the Persian king assembled a truly massive force, including elite cavalry units and war elephants.

Alexander divided his forces, leading one flank while his trusted general Parmenion commanded the other. Spotting a weakness in the Persian center, Alexander led a direct charge, forcing Darius to flee once more. With that, the heart of the Persian Empire collapsed, and Alexander was crowned «King of Kings.»

The Persian Gates: Overcoming the Last Stand

In 330 BCE, Alexander met fierce resistance at the Persian Gates, a narrow mountain pass on the way to the ceremonial capital of Persepolis.

Led by satrap Ariobarzanes, the Persians ambushed Alexander’s forces, inflicting heavy losses. But after a month-long standoff, Alexander outflanked the defenders and broke through. This final stand marked the symbolic end of the Achaemenid Empire.

Into India: The Battle of the Hydaspes

After consolidating control in Central Asia—sealed through his marriage to Roxana—Alexander turned his attention to India. At the Battle of the Hydaspes in 326 BCE, he faced King Porus, a formidable opponent commanding war elephants and a large army.

Despite the odds, Alexander triumphed and, impressed by Porus’ bravery, allowed him to retain power as a regional satrap. This was Alexander’s last major battle, as his troops, exhausted and far from home, refused to march further east.

A Legacy That Shaped Civilizations

By the time of his death in 323 BCE, Alexander had built the largest empire the world had ever seen. But his legacy went beyond territory.

He founded over 20 cities, the most famous being Alexandria in Egypt, which became a hub of learning and culture. His campaigns connected distant regions, sparked global trade, and spread Hellenistic culture across three continents.

Roman emperors admired him, military academies still study his tactics, and historians regard him as one of the most influential figures in history.

Final Thoughts

Alexander the Great was more than just a conqueror. He was a visionary, a strategist, and a unifier who reshaped the ancient world. Through diplomacy, warfare, and relentless ambition, he carved a legacy that still echoes across continents and centuries.