As was expected, the Lacedæmonians invaded Attica, but the Corinthians refused to support them, and this attempt to procure the restoration of Hippias failed. Thus baffled, they summoned a meeting of their allies, at which the banished chief was invited to be present; but here again their views were frustrated by the agency of the Corinthians. Hippias returning to Sigeum went thence to Sardis, with the view of persuading the satrap Artaphernes to reduce Athens, and replace him in the monarchy, under vassalage to the Persian monarch. The Athenians on receiving these tidings sent to request Artaphernes not to listen to their banished subjects; but they were met by a peremptory command to receive back Hippias as they wished to be safe. From this time they considered themselves openly at war with Persia. Under these circumstances, when an insurrection broke out among the Asiatic Greeks of Ionia and Æolis, the Athenians readily gave their assistance to the revolters. Twenty ships of theirs, with five of the Eretrians, joined the Ionian fleet; the collective force disembarked at Ephesus, marched sixty miles into the interior, took Sardis by surprise, and burnt it. Returning, they were entirely defeated under the walls of Ephesus, and the Athenians then withdrew their ships, and took no further part in the war. These events took place B.C. 499. After the Ionians were subdued, Darius bent himself to revenge the destruction of Sardis upon the Athenians and Eretrians. In the year 492 Mardonius led an army against them through Macedonia, but it suffered such severe losses by land and sea, that he returned to winter in Asia, without having reached even the borders of Greece. The following year heralds were sent into Greece to demand of every city earth and water in token of submission. Many obeyed, but Lacedæmon and Athens refused, and cruelly threw the heralds at the one place into a pit, at the other into a well, bidding them take from thence earth and water. In 490 Darius sent a second armament under command of Datis and Artaphernes. They crossed the Ægean Sea, to avoid the tedious march through Macedonia, landed in Eubœa, reduced and enslaved the Eretrians, and thence under the guidance of Hippias sailed to Marathon, on the north–east coast of Attica.