About 508 B. C. Darius invaded Scythia, and, crossing the Danube,
marched far into the territory which is now European Russia; but the
expedition ended in a retreat without encountering the enemy, and with
great loss of men from famine. On his return his generals subdued Thrace
and Macedonia, north of Greece, and added them to the Persian Empire.
His famous war with the Greeks arose out of the revolt of the Ionian
Greek cities in Asia Minor in 501, and the burning of the city of Sardis
by their Athenian allies. An expedition sent against Greece under the
general Mardonius, in 492 B. C., was defeated by the Thracians on land,
and frustrated by a storm in the Ægean Sea. In 490 a great armament was
sent by Darius under Datis and Artaphernes, and then was fought the
decisive battle of Marathon. Darius’s proposed and long-prepared revenge
upon the Greeks was baffled by a rebellion in Egypt; and he died in 485,
leaving the task to his son and successor, Xerxes.