11 The First Peloponnesian War

In 461 B.C., the Spartans and Athenians clashed in what is often called First Peloponnesian War (461–446 B.C.). The immediate catalyst of the initial clash was the election by the Athenian assembly of the radical democrat Pericles, who concluded anti-Spartan treaties with Argos and Thessaly. In 461 B.C., democrats seized Megara and entered into an alliance with Athens. The Spartans declared war because Megara controlled the strategic routes out of the Peloponnesus, preventing Sparta from invading Attica. In 461–459 B.C., the Athenian navy swept the Peloponnesians from the seas and captured Aegina. In 457 B.C., the Athenians twice invaded Boeotia. At the Battle of Tanagra, they fought the Spartans to a draw; two months later, they defeated the Boeotians and imposed democracies in central Greece. It was only Athenian setbacks in Egypt in 455/4 B.C. that compelled Pericles to negotiate an armistice with the Spartans and to conclude a peace with Persia in 451 B.C. In 447/6 B.C., Boeotian and Megarian exiles restored oligarchic governments and returned to the Spartan alliance. Rather than fight, Pericles and the Spartan king negotiated, and as a result Sparta recognized the integrity of Athens and her Aegean empire.