In 409 BC, Darius II, King of Persia (the Achaemenid Empire), decided to join the Sparta led Peloponnesian League which was at war against the Athens led Delian League. He was convinced that Athenian power was broken after the failure of their Sicilian Expedition between 415–413 BC, and that now the victory of the Spartan side was certain. He ordered his satraps in Asia Minor, Tissaphernes and Pharnabazus, to assist Sparta in defeating Athens.
Tissaphernes and Pharnabazus organized funds for rebuilding the Spartan fleet which had been routed in the Battle of Cyzicus (410 BC) by the Athenian fleet led by Alcibiades, Thrasybulus, and Theramenes. They agreed to pay the salaries of the Spartan sailors who were operating the Spartan fleet in Aegean or Hellespontine waters. With their funds, the salaries of the Peloponnesian crew went up and that inspired several sailors and soldiers on the Athenian side to defect to the Peloponnesian side.
In 408 BC, Cyrus the Younger, second son of Darius II, arrived in Asia Minor to ensure that the war against Athens was being vigorously pursued. He could not be more than 16 at that time, since he was born after Darius II ascended to the throne in 423 BC, but he had the plenipotentiary power to coordinate the Persian war strategy. Cyrus decided that a Peloponnesian victory was in his interest. He was aiming to kill his elder brother Artaxerxes II and capture the throne of the Persian Empire after his father’s death.
Cyrus believed that in return for the help that he was giving to the Peloponnesian side, the Greeks would provide him with hoplite soldiers to defeat his brother’s army. He was impressed by Lysander, the Spartan Admiral. Lysander was a polished courtier, a suave strategist, and a brilliant general. He understood what Cyrus desired. and Cyrus in turn realized that Lysander had the capacity to win the war. With the substantial sum of money that Cyrus delivered to him, Lysander expanded the Spartan fleet.
The Spartans knew that the Athenians would never accept defeat until they were decisively beaten in a sea battle. The Spartan and Athenian sides fought two naval battles in 406 BC, neither of which proved decisive. In the first battle, the Spartan side had an edge and in the second the Athenian side prevailed. In 405 BC, the Spartans showed interest in negotiating the terms of peace with the Athenians who refused to negotiate unless the Spartans gave them the Ionian cities in Asia Minor. The Spartans could not do that because they had already promised the Ionian cities to the Persians.
Meanwhile the Spartans recalled Lysander in 405 BC. He had been retired in 406 BC in accordance with the Spartan law. Lysander used his connections with Cyrus to quickly raise funds for adding more vessels and crew to the Spartan navy.
With his fleet, Lysander sailed into Hellespont in the summer of 405 BC, He captured and destroyed a number of cities and islands that were allied to Athens. Colonists from these cities and islands fled to Athens making the city swell with refugees. With its navy gone, and being surrounded by the Spartan forces on all sides, Athens could not procure food for its population. The worst thing from the Athenian perspective was that they did not have the funds to rebuild their fleet. The Athenian assembly authorized Theramenes to negotiate the peace terms. Theramenes convinced the Spartans that Athens should not be sacked, as many of the allies of Sparta (like Corinth) had been insisting.
Having won the Peloponnesian War, the Spartans now had to help Cyrus become the King of Persia. Soon after Cyrus arrived in Asia Minor to coordinate the war against Athens, Darius II had fallen ill. He died in 404 BC, and Artaxerxes II was proclaimed the new King. Time was running out for Cyrus. He had to declare war before Artaxerxes had the time to consolidate his rule. The Spartans raised an army of 10,000 Greek hoplites to fight for Cyrus. These 10,000 hoplites joined a Persian army of 30,000 that Cyrus and his generals had raised. In 401 BC, Cyrus made his bold move—with his army of 40,000, he marched through Asia Minor, towards Babylon.
Artaxerxes gathered his own army. The two armies met in 401 BC, at the Battle of Cunaxa. The Greek hoplites won the war, but Cyrus was killed. Cyrus was a hothead. When he saw his brother on the battlefield, he broke out of the protective ring of bodyguards around him and charged at his brother. He was surrounded by the enemy troops and cut down. With the prince for whom they had arrived to fight the war dead, the Greeks were in a terrible state of confusion. They decided to negotiate with Artaxerxes. But the negotiation was a trap. Artaxerxes had the Greek generals, who arrived in his camp for carrying out the negotiations, decapitated.
The Greeks then elected new generals. One of these generals was Xenophon, the Athenian philosopher and historian. In his seven volume work the Anabasis, Xenophon has described the spectacular retreat of the Greek forces from Persia. The Greek hoplites marched for weeks through the desert where little food was available. They marched through snow-filled mountain passes. They fought several battles on their way. Whatever they needed to sustain themselves, they got through force or diplomacy. Their aim was to reach the Black Sea where some Greek cities were located. The word “Anabasis” is generally translated as The March Up Country or as The March of the Ten Thousand.
Xenophon’s account of the exploits of the 10,000 Greek hoplites in Persia became famous in the Greek world. The Greeks did not see the seven books of Anabasis as a story of retreat through Persia but as a blueprint for defeating the Persian Empire. Three generations later, Alexander (the future Alexander the Great) used the information in the Anabasis to develop a military strategy for capturing the Persian Empire.