Harpagus； although the Persians then possessed no fleet to force them to obedience。 Samos； on the other hand； maintained its independence； and appears soon afterwards one of the most powerful of the Grecian states。
During the reign of Cambyses （B。C。 529…521）； the son and successor of Cyrus； the Greek cities of Asia remained obedient to their Persian governors。 It was during this reign that Polycrates； tyrant of Samos； became the master of the Grecian seas。 The ambition and good fortune of this enterprising tyrant were alike remarkable。 He possessed a hundred ships of war； with which he conquered several of the islands； and he aspired to nothing less than the dominion of Ionia； as well as of the islands in the AEgean。 The Lacedaemonians； who had invaded the island at the invitation of the Samian exiles； for the purpose of overthrowing his government； were obliged to retire； after besieging his city in vain for forty days。 Everything which he undertook seemed to prosper； but his uninterrupted good fortune at length excited the alarm of his ally Amasis； the king of Egypt。 According to the tale related by Herodotus； the Egyptian king； convinced that such amazing good fortune would sooner or later incur the envy of the gods； wrote to Polycrates； advising him to throw away one of his most valuable possessions and thus inflict some injury upon himself。 Thinking the advice to be good； Polycrates threw into the sea a favourite ring of matchless price and beauty； but unfortunately it was found a few days afterwards in the belly of a fine fish which a fisherman had sent him as a present。 Amasis now foresaw that the ruin of Polycrates was inevitable； and sent a herald to Samos to renounce his alliance。 The gloomy anticipations of the Egyptian monarch proved well founded。 In the midst of all his prosperity Polycrates fell by a most ignominious fate。 Oroetes； the satrap of Sardis； had for some unknown cause conceived a deadly hatred against the Samian despot。 By a cunning stratagem the satrap allured him to the mainland； where he was immediately arrested and hanged upon a cross （B。C。 522）。
The reign of Darius； the third king of Persia。 （B。C。 521…485）； is memorable in Grecian history。 In his invasion of Scythia； his fleet； which was furnished by the Asiatic Greeks； was ordered to sail up the Danube and throw a bridge of boats across the river。 The King himself； with his land forces； marched through Thrace； and； crossing the bridge； placed it under the care of the Greeks； telling them that； if he did not return within sixty days； they might break it down； and sail home。 He then left them； and penetrated into the Scythian territory。 The sixty days had already passed away； and there was yet no sign of the Persian army； but shortly afterwards the Greeks were astonished by the appearance of a body of Scythians； who informed them that Darius was in full retreat； pursued by the whole Scythian nation； and that his only hope of safety depended upon that bridge。 They urged the Greeks to seize this opportunity of destroying the Persian army； and of recovering their own liberty； by breaking down the bridge。 Their exhortations were warmly seconded by the Athenian Miltiades； the tyrant of the Thracian Chersonesus； and the future conqueror of Marathon。 The other rulers of the Ionian cities were at first disposed to follow his suggestion； but as soon as Histiaeus of Miletus reminded them that their sovereignty depended upon the support of the Persian king； and that his ruin would involve their own； they changed their minds and resolved to await the Persians。 After enduring great privations and sufferings Darius and his army at length reached the Danube and crossed the bridge in safety。 Thus the selfishness of these Grecian despots threw away the most favourable opportunity that ever presented itself of delivering their native cities from the Persian yoke。 To reward the services of Histiaeus； Darius gave him the town of Myrainus； near the Strymon。 Darius； on his return to Asia； left Megabazus in Europe with an army of 80；000 men to complete the subjugation of Thrace and of the Greek cities upon the Hellespont。 Megabazus not only subdued the Thracians； but crossed the Strymon； conquered the Paeonians； and penetrated as far as the frontiers of Macedonia。 He then sent heralds into the latter country to demand earth and water； the customary symbols of submission。 These were immediately granted by Amyntas； the reigning monarch （B。C。 510）； and thus the Persian dominions were extended to the borders of Thessaly。 Megabazus； on his return to Sardis； where Darius awaited him； informed the Persian monarch that Histiaeus was collecting the elements of a power which might hereafter prove formidable to the Persian sovereignty； since Myrcinus commanded the navigation of the Strymon； and consequently the commerce with the interior of Thrace。 Darius； perceiving that the apprehensions of his general were not without foundation； summoned Histiaeus to his presence； and； under the pretext that he could not bear to be deprived of the company of his friend； carried him with the rest of the court to Susa。 This apparently trivial circumstance was attended with important consequences to the Persian empire and to the whole Grecian race。
For the next few years everything remained quiet in the Greek cities of Asia； but about B。C。 502 a revolution in Naxos； one of the islands in the AEgean Sea； first disturbed the general repose； and occasioned the war between Greece and Asia。 The aristocratical exiles； who had been driven out of Naxos by a rising of the people； applied for aid to Aristagoras； the tyrant of Miletus and the son…in…law of Histiaeus。 Aristagoras readily promised his assistance； knowing that； if they were restored by his means； he should become master of the island。 He obtained the co…operation of Artaphernes； the satrap of western Asia by holding out to him the prospect of annexing not only Naxos； but all the islands of the AEgean sea； to the Persian empire。 He offered at the same time to defray the expense of the armament。 Artaphernes placed at his disposal a fleet of 200 ships under the command of Megabates； a Persian of high rank； but Aristagoras having affronted the Persian admiral； the latter revenged himself by privately informing the Naxians of the object of the expedition； which had hitherto been kept a secret。 When the Persian fleet reached Naxos they experienced a vigorous resistance； and at the end of four months they were compelled to abandon the enterprise and return to Miletus。 Aristagoras was now threatened with utter ruin。 Having deceived Artaphernes； and incurred the enmity of Megabates； he could expect no favour from the Persian government； and might be called upon at any moment to defray the expenses of the armament。 In these difficulties he began to think of exciting a revolt of his countrymen； and while revolving the project he received a message from his father…in… law； Histiaeus； urging him to this very step。 Afraid of trusting any one with so dangerous a message； Histiaeus had shaved the head of a trusty slave； branded upon it the necessary words； and as soon as the hair had grown again sent him off to Miletus。 His only motive for urging the Ionians to revolt was the desire of escaping from captivity at Susa； thinking that Darius would set him at liberty in order to put down an insurrection of his countrymen。 The message from Histiaeus fixed the wavering resolution of Aristagoras。 He forthwith called together the leading citizens of Miletus； laid before them the project of revolt； and asked them for advice。 They all approved of the scheme； with the exception of Hecataeus； one of the earliest Greek historians。 Aristagoras laid down the supreme power in Miletus； and nominally resigned to the people the management of their own affairs。 A democratical form of government was established in the other Greek cities of Asia； which thereupon openly revolted from Persia （B。C。 500）。
Aristagoras now resolved to cross over to Greece； in order to solicit assistance。 The Spartans； to whom he first applied； refused to take any part in the war； but at Athens he met with a very different reception。 The Athenians sympathised with the Ionians as their kinsmen and colonists； and were incensed against the satrap Artaphernes； who had recently commanded them to recall Hippias。 Accordingly they voted to send a squadron of twenty ships to the assistance of the Ionians； and in the following year （B。C。 499） this fleet； accompanied by five ships from Eretria in Euboea； crossed the AEgean。 The troops landed at Ephesus； and； being reinforced by a strong body； of Ionians； marched upon Sardis。 Artaphernes was taken unprepared； and not having sufficient troops to man the walls； he retired into the citadel； leaving the town a prey to the invaders。 Accordingly they entered it unopposed； and while engaged in pillage； one of the soldiers set fire to a house。 As most of the houses were built of wickerwork and thatched with straw； the flames rapidly spread； and in a short time the whole city was in flames。 The Greeks； on their return to the coast； were overtaken by a large Persian force and defeated with great slaughter。 The Athenians ha