Greece and Persia: Wars, Alliances, and the Fate of the Ancient World

The foundation of Greek civilization was the polis, the city-state. Politically autonomous communities, often isolated by the country's mountainous terrain, consisted of walled cities with villages and agricultural lands outside. Proud of their independence, the hundreds of cities scattered around the Mediterranean nevertheless shared a common language, religion, customs, and culture. Even the most remote colonies sought to assert their identity by building temples and theaters and producing refined ceramics.

On some occasions, the Greek world united in broad confederations, particularly in the face of the threat of Persian invasion. 

Following a series of revolts in the western provinces, in 492 BC the vast Persian Empire pushed westward in an attempt to conquer the Greek city-states and the colonies around the Aegean Sea. This led to a series of destructive wars in which tactical superiority helped the Greeks stop the Persians, who were far superior in numbers.

Around 550 BC, the Persian Empire had expanded westward into Anatolia, where its armies defeated Croesus, the powerful king of Lydia, and conquered numerous cities of Ionia, until then Greek colonies. However, in 499 BC the Greeks of the Ionian city of Miletus rebelled against Persian rule, triggering a series of uprisings not only in Ionia but also in cities beyond the western Persian frontier.

The Persian military response was swift, but it took the empire's forces five years to suppress the revolt, finally recapturing Miletus in 494 BC. Subsequently, as retaliation for the support given by the Greek city-states of Athens and Eretria to the Ionian cities during the revolt, in 492 BC the Persian king Darius I (reign 522-486 BC) launched a military invasion of Greece. The attack was twofold: a land and naval campaign toward Thrace and Macedonia led by the general Mardonius, and a second expedition commanded by Datis and Artaphernes. Many Greek cities thus fell under Persian control, while Macedonia became a client state. However, in the end, when a storm wrecked Mardonius' fleet off Mount Athos, the Persians were forced to withdraw. In 490 BC, at Marathon, the second army was defeated by the smaller but tactically better prepared Athenian contingent.

Ten years later, Darius' son and successor, Xerxes I (reign 486-465 BC), after years of planning his campaign, resumed hostilities against Athens. Once again, Persian forces were numerically superior to the Greek ones, partly because the Athenians were not always able to persuade the other Greek states—particularly the militarily led city of Sparta—to unite in battle. Nevertheless, the Persians were unable to exploit this advantage, and with the victories at Salamis and Plataea, the city-states secured their independence.

550-486 BC

Darius I was the third Persian king of the Achaemenid Empire; during his reign, the empire reached its peak. His administrative skills, combined with the strength and intelligence of his command, earned him the epithet Darius the Great. He built the magnificent city of Persepolis and left inscriptions recounting the story of his achievements.

The young Macedonian king Alexander III ascended the throne in 336 BC upon his father's death, inheriting an extremely efficient army. In just ten years he conquered the vast Persian Empire, creating a realm that stretched from Greece to the Indus River. Although Alexander's empire quickly fragmented after his death, it left a cultural legacy throughout the region that was destined to endure.

Upon his accession to the Macedonian throne in 359 BC, Philip II (reign 359-336 BC) transformed his army into the most effective war machine of the ancient world, based on the heavy infantry of the phalanx armed with long pikes. During his reign, his armies successfully conducted sieges to take control of Thessaly, Illyria, and Thrace and, despite popular hostility, asserted control over mainland Greece. However, in 336 BC, as Philip was preparing to invade Persia, he was assassinated by one of his personal guards.

The twenty-one-year-old son of Philip, Alexander III, immediately claimed the throne and used military force to suppress the revolts that broke out in Greece and the Balkans after his father's death. He then decided to fulfill Philip's ambitions, leading an army of 30,000 infantry and 5,000 cavalry in a masterfully conducted campaign to conquer the Persian Empire. He swept through the Persian territories of Anatolia, Syria, and Egypt without losing a single battle, then marched east toward Persia, conducting an unstoppable campaign that in 373 BC led him to definitively defeat the Achaemenid dynasty.

It was also a fundamental and unrepeatable era: the blending of Eastern and Western cultures led to the birth of a new cultural world that profoundly influenced subsequent ages. Alexander's empire fragmented after his sudden death in Babylon in 323 BC, at just thirty-two years of age, probably from fever or causes still debated. His death was followed by a struggle for power that resulted in the division of the empire.