Reasons which induced Croesus to invade Media.--The Lacedaemonians.--Embassadors to Sparta.--Preparations of Croesus.--The counsel of Sardaris.--The army begins to march.--Thales the Milesian.--Mathematical skill of Thales.--His theorems.--Ingenious plan of Thales for crossing the Halys.--Advance of Cyrus.--Preparations for battle.--Great battle at Pteria.--Undecisive result.--Croesus returns to Sardis.--Cyrus follows him.--Confusion and alarm at Sardis.--The Lydian cavalry.--Nature of cavalry.--Manner of receiving a cavalry charge.--The camels.--Cyrus opposes them to the cavalry.--The battle fought.--Cyrus victorious.--Situation of Sardis.--Its walls.--An ancient legend.--Cyrus besieges the city.--The reconnoissance.--The walls scaled.--Storming of the city.--Croesus made prisoner.--The funeral pile.--Anguish and despair of Croesus.--The saying of Solon.--Croesus is saved.--He becomes Cyrus's friend.--Croesus sends his fetters to the oracle at Delphi.--Explanations of the priests.--Their adroitness and dexterity. There were, in fact, three inducements which combined their influence on the mind of Croesus, in leading him to cross the Halys, and invade the dominions of the Medes and Persians: first, he was ambitious to extend his own empire; secondly, he feared that if he did not attack Cyrus, Cyrus would himself cross the Halys and attack him; and, thirdly, he felt under some obligation to consider himself the ally of Astyages, and thus bound to espouse his cause, and to aid him in putting down, if possible, the usurpation of Cyrus, and in recovering his throne. He felt under this obligation because Astyages was his brother-in-law; for the latter had married, many years before, a daughter of Alyattes, who was the father of Croesus. This, as Croesus thought, gave him a just title to interfere between the dethroned king and the rebel who had dethroned him. Under the influence of all these reasons combined, and encouraged by the responses of the oracle, he determined on attempting the invasion. The first measure which he adopted was to form an alliance with the most powerful of the states of Greece, as he had been directed to do by the oracle. After much inquiry and consideration, he concluded that the Lacedaemonian state was the most powerful. Their chief city was Sparta, in the Peloponnesus. They were a warlike, stern, and indomitable race of men, capable of bearing every possible hardship, and of enduring every degree of fatigue and toil, and they desired nothing but military glory for their reward. This was a species of wages which it was very easy to pay; much more easy to furnish than coin, even for Croesus, notwithstanding the abundant supplies of gold which he was accustomed to obtain from the sands of the Pactolus.