, sent to the
apparently insignificant Greek states were insolently rejected. Darius
sent an expedition to punish Athens in particular, and the Athenians
drove his army into the sea at the battle of Marathon.

Xerxes, son of Darius, organised an overwhelming force by land and sea
to eat up the Greeks. The invaders were met but hardly checked at
Thermopylae, where Leonidas and the immortal three hundred fell; all
Greece north of the Isthmus of Corinth was in their hands, including
Athens. But their fleet was shattered to pieces, chiefly by the
Athenians under Themistocles and Aristides at Salamis, and the
destruction of their land forces was completed by the united Greeks at
Plataea. A further disaster was inflicted on the same day at Mycale.

_II.--The Struggles of Athens and Sparta_

Meanwhile, the Sicilian Greeks, led by Gelo of Syracuse, successfully
resisted and overthrew the aggression of Carthage, the issue being
decided at the battle of Himera. The part played by Athens under the
guidance of Themistocles in the repulse of Persia gave her a new
position among the Greek states and an indisputable naval leadership. As
the maritime head of Hellas she was chief of the naval Delian League,
now formed ostensibly to carry on the war against Persia. But the
leaguers, who first contributed a quota of ships, soon began to
substitute money to provide ships, which in effect swelled the Athenian
navy, and turned the contributors into tributaries. Thus, almost
automatically, the Delian League converted itself into an Athenian
empire. In Athens itself an unparalleled personal ascendancy was
acquired by Pericles, who made the form of government and administration
more democratic than before. But this growing supremacy of Athens
aroused the jealous alarm of other Greek states. Sparta saw her own
titular hegemony threatened; the subject cities grew restive under the
Athenian yoke. Sparta came forward professedly as champion of the
liberties of Hellas; Athens, guided by Pericles, refused to submit to
Spartan dictation, and accepted the challenge which plunged Greece into
the Peloponnesian war.

The Athenians concentrated on the expansion of their naval armaments,
left the open country undefended and gathered within the city walls, and
landed forces at will on the Peloponnese. Platsea, almost their sole
ally on land, held out valiantly for some time, but was forced to
surrender; and Athens herself suffered frightfully from a