Foreign Invasion: The Great War That Crumbled Iran After 200 Years of Prosperity

Jakarta, CNBC Indonesia — Iran was once left in ruins after being attacked by foreign powers. The event happened more than 2,300 years ago, when the region now known as Iran was the Persian Empire and one of the largest empires in the world.

Its 200 years of glory collapsed after being attacked by a young conqueror from Macedon, Alexander the Great. In a series of great wars, Alexander’s forces toppled the empire then led by Darius III.

At that time, Persia was under the rule of the Achaemenid Dynasty centred in the region now known as Iran. Its territory stretched from Central Asia to Egypt, including areas now part of Turkey, Iraq, Syria, and parts of Central Asia.

Although vast and with a strong army, the empire began to face internal problems, including political strife and the central authority’s waning control over the distant provinces.

According to History.com, the situation was exploited by Alexander to launch a military expansion into the Persian realm. Alexander himself was the son of the Macedonian king, Philip II, who had previously built up the Macedonian military to be very strong.

After his father was killed in 336 BC, Alexander ascended the throne at the age of 20 and inherited a well-trained army and a large ambition to expand his territory. One of his main targets was Iran. In addition to continuing the expansion plans his father had prepared, Alexander also wanted to avenge the long-running Greek–Persian conflicts.

In 334 BC, Alexander led the Macedonian army across Asia Minor to begin a campaign to conquer the empire then considered the world’s greatest power.

Citing Britannica, although the Persian forces were far larger, Alexander relied on clever tactics and disciplined troops. The conflict between the two powers then unfolded across a series of major battles that determined the fate of the Persian Empire.

The first battle occurred at the Granicus River (now in Turkey) and ended in an Alexander victory. This success opened the way for the Macedonian army to dominate Asia Minor.

Not long afterwards, a major battle occurred again at Issus. In that war, Alexander’s forces again defeated the Persian army and forced King Darius III to flee the field.

Yet the decisive battle occurred in 331 BC in the Battle of Gaugamela. Citing Britannica, in this battle Darius III deployed forces far larger than Alexander’s.

Nevertheless, Alexander used a cautious strategy by drawing the Persian lines out of their positions. When a gap opened at the centre of the enemy’s defence, he led a cavalry assault directly towards Darius’s position.

That attack triggered chaos in the Persian ranks. Darius III again fled the field, while his troops were scattered. This defeat marked the turning point that toppled Persia as the world’s leading power for 200 years.

After that victory, Alexander’s forces moved on to seize key Persian cities, including Babylon, Susa, and Persepolis, one of the empire’s capitals.

The capture of Persepolis became a symbol of the empire’s downfall. The city, once the centre of Persian splendour, was later set alight by Alexander’s troops.

Shortly after, Darius III was killed while fleeing from Alexander’s pursuit. This event marked the end of the Achaemenid Dynasty’s rule over Persia for more than two centuries. Nevertheless, the region of Iran continued to undergo changes of power, eventually becoming the Islamic Republic of Iran in the modern era.