The aristocratical party, enraged at these reforms called in the assistance of Cleomenes, king of the Lacedaemonians. Athens was menaced by foreign enemies and distracted by party struggles. Clisthenes was at first compelled to retire from Athens; but the people rose in arms against Cleomenes, expelled the Lacedaemonians, who had taken possession of the city, and recalled Clisthenes. Thereupon Cleomenes collected a Peloponnesian army in order to establish Isagoras as a tyrant over the Athenians, and at the same time he concerted measures with the Thebans and the Chalcidians of Euboea for a simultaneous attack upon Attica. The Peloponnesian army, commanded by the two kings, Cleomenes and Demaratus, entered Attica, and advanced as far as Eleusis; but when the allies became aware of the object for which they had been summoned, they refused to march farther, and strongly protested against the attempt to establish a tyranny at Athens. Their remonstrances being seconded by Demaratus, Cleomenes found it necessary to abandon the expedition and return home. At a later period (B.C. 491) Cleomenes took revenge upon Demaratus by persuading the Spartans to depose him upon the ground of illegitimacy. The exiled king took refuge at the Persian court. The unexpected retreat of the Peloponnesian army delivered the Athenians from their most formidable enemy, and they lost no time in turning their arms against their other foes. Marching into Boeotia, they defeated the Thebans and then crossed over into Euboea, where they gained a decisive victory over the Chalcidians. In order to secure their dominion in Euboea, and at the same time to provide for their poorer citizens, the Athenians distributed the estates of the wealthy Chalcidian landowners among 4000 of their citizens, who settled in the country under the name of CLERUCI. The successes of Athens excited the jealousy of the Spartans, and they now resolved to make a third attempt to overthrow the Athenian democracy. They had meantime discovered the deception which had been practised upon them by the Delphic oracle; And they invited Hippias to come from Sigeum to Sparta, in order to restore him to Athens. The experience of the last campaign had taught them that they could not calculate upon the co-operation of their allies without first obtaining their approval of the project; and they therefore summoned deputies from all their allies to meet at Sparta, in order to determine respecting the restoration of Hippias. But the proposal was received with universal repugnance; and the Spartans found it necessary to abandon their project. Hippias returned to Sigeum, and afterwards proceeded to the court of Darius.