The Battle of the Arginus Islands took place in 406 BC at the town of Canae on the Arginus Islands (east of Lesbos). This battle was part of the Peloponnesian War fought between Athens and Sparta.
The Battle of Arginus was preceded by the victory of Sparta and the blockade of the Athenian fleet. An inexperienced fleet was sent from Athens to liberate the Athenian fleet, but it was able to prevail thanks to capable commanders and entirely new tactics.
The Spartan fleet was led by Kallikratidas, a man who disliked the Persians and assembled the fleet only with the help of Spartan allies. His predecessor, Lysandros, on the other hand, was a supporter of the Persians and their prince, Cyrus the Younger.
Kallikratidas assembled a fleet of about 140 triremes, while the Athenian commander Conon could only assemble 70 triremes. Kallikratidas set off for the island of Lesbos to take it so that he could move on to the Hellespont and cut off a vital grain supply route to Athens. In order to defend Lesbos, Conon had to fight the Spartans, although he clearly had a numerically weaker fleet. But the Spartan attack was so strong that Conon had to retreat to Mytilene. Here the Spartan fleet cut him off both on water and on land. With a good deal of luck, the Athenian commander managed to send one ship to Athens carrying news of the situation.
Once the message was relayed to Athens, they immediately began building a new fleet. Funding was provided by the melting down of the golden statue of the goddess Nike, and slaves and metoics were recruited into the crews. To ensure the slaves' obedience, they gave citizenship to those on the ships. In all, the Athenians composed 150 triremes commanded by eight strategists (Aristocrates, Aristogenes, Diomedon, Erasinid├¬s, Lysias, Pericles the Younger, Pr├│tomachos and Thrasyllos).
The Spartans learned of the Athenians' movements and Kallikratidas therefore decided to attack them at night. However, due to a heavy storm, the attack was postponed until the morning. In the morning, 140 Spartan ships set out (the other 50 guarded Conon in Mytilene) against 150 Athenian ships. The Spartans were more experienced, which was a first, but the Athenians used a new tactic. First, they divided the entire fleet into eight groups, with each group having its own commander. Next, they sailed in two lines (normally they sailed in one line), thus preventing the Spartans from using a maneuver known as "diekpl├║s".
The Spartans responded to this Athenian strategy by splitting their forces in two (although the helmsman advised Kallikratides that the Spartans should withdraw) and the battle began. Eventually Kallikratidas, who led the right flank, was killed and the resistance on the right collapsed. The left wing resisted, but could no longer hold the entire Athenian fleet and therefore retreated. In all, the Spartans lost 70 ships, while the Athenians lost 25.
Consequently, it was necessary to liberate Conon while rescuing the survivors of the 25 sunken ships. But both these actions were thwarted by a violent storm. When news of the victory spread in Athens, everyone rejoiced. But it was soon discovered that the soldiers from the 25 sunken ships had not been rescued. The people were outraged and demanded punishment. As a result, six of the eight strategists were executed and the other two fled.
The Spartans tried to make peace with Athens after this defeat, but Athens refused. Subsequently, Lysandros took command of the Spartan fleet, and the conflict between Athens and Sparta resulted in the Battle of Aigospotamoi. Here, the Spartans (with the support of the Persians) won, thus winning the entire Peloponnesian War.