and Spartans came to besiege him in Samos without manifesting any respect for the great king. They failed in this particular enterprise,* but later on, after Oroetes had been seized and put to death, it was to the Spartans that the successor of Polycrates, Maaandrios, applied for help to assert his claim to the possession of the tyranny against Syloson, brother of Polycrates and a personal friend of Darius.** * The date of the death of Polycrates must be placed between that of the conquest of Egypt and that of the revolt of Gaumata, either in 524 or 523 B.C. ** The reinstatement of Syloson may be placed in 516 B.C., about the time when Darius was completing the reorganisation of the empire and preparing to attack Greece. This constant intervention of the foreigner was in evident contradiction to the spirit which had inspired the reorganisation of the empire. Just when efforts were being made to strengthen the imperial power and ensure more effective obedience from the provincials by the institution of satrapies, it was impossible to put up with acts of unwarrantable interference, which would endanger the prestige of the sovereign and the authority of his officers. Conquest presented the one and only natural means of escape from the difficulties of the present situation and of preventing their recurrence; when satraps should rule over the European as well as over the Asiatic coasts of the AEgean, all these turbulent Greeks would be forced to live at peace with one another and in awe of the sovereign, as far as their fickle nature would allow. It was not then, as is still asserted, the mere caprice of a despot which brought upon the Greek world the scourge of the Persian wars, but the imperious necessity of security, which obliges well-organised empires to subjugate in turn all the tribes and cities which cause constant trouble on its frontiers. Darius, who was already ruler of a good third of the Hellenic world, from Trebizond to Barca, saw no other means of keeping what he already possessed, and of putting a stop to the incessant fomentation of rebellion in his own territories, than to conquer the mother-country as he had conquered the colonies, and to reduce to subjection the whole of European Hellas. CHAPTER II--THE LAST DAYS OF THE OLD EASTERN WORLD _THE MEDIAN WAR--THE LAST NATIVE DYNASTIES OF EGYPT--THE EASTERN WORLD ON THE EVE OP THE MACEDONIAN CONQUEST._ _The Persians in 512 B.C.--European Greece and the dangers which its independence presented to the safety of the empire--The preliminaries of the Median wars: the Scythian expedition, the conquest of Thrace and Macedonia--The Ionic revolt, the intervention of Athens and the taking of Sardes; the battle of Lade--Mardonius in Thrace and in Macedonia._