Some years later Cyrus returned home and, shortly after, a faction of the Medes who had become devoted to the Persian prince and felt dissatisfied with the tyranny of their king, informed Cyrus that if he would bring an army against the Medes, they would cause the Median forces to desert to him. Another account says that Cyrus himself planned the conquest while at the Median court, and having feasted his attendants and led them to drink heavily, escaped to Persia, where he soon persuaded his father to march against the Medes. In either case, it would seem that the prince had learned the true condition of degenerated Media, and determined to free his own land from the hated tribute service--establishing its independence. In the battle which was waged against the two people, Astyages was taken captive, and when the majority of the soldiers went over to the Persian side, the remaining soldiers fled. Cyrus allowed Astyages to retain his own personal attendants, and permitted him to live in a style befitting his recent position. Under guard of Persian soldiers, he was free to go about at will. It is probable that Cyrus had at first no greater ambition than to free Persia from tribute imposed by Media, but the desire for conquest once awakened never ceases while lands remain unwon. In conquering Media, all territories of Assyria fell to Cyrus' portion. The Medes had held lands to the river Halys on the northwest. Beyond this boundary stream the empire of Lydia had been growing under the rule of Croesus. Croesus has become proverbial for his wealth. As he extended the boundaries of Lydia, he grew wealthier still, until his resources exceeded all estimate. Having lost a favorite son, he lived in seclusion until a sense of approaching danger roused him to defend his kingdom. The river Halys was a narrow stream--too small by far to prove a lasting barrier against an aggressive nation. To spare his land the ravages of war, Croesus determined to invade the land of his rival. He thought best to consult the oracle at Delphi before entering upon such a serious campaign. Having sent costly presents to Delphi, Croesus inquired whether or not it would be safe for him to proceed against Persia. The reply was that if Croesus crossed the Halys and carried war into Persia, a mighty kingdom would be overthrown, and that he would do well to form an alliance with the strongest Greek state.