This expedition was headed by a Grecian general named Clearchus. The soldiers and the subordinate officers of the expedition did not know for what special service it was designed, as Cyrus had a treasonable and guilty object in view, and he kept it accordingly concealed, even from the agents who were to aid him in the execution of it. His plan was to make war upon and dethrone his brother Artaxerxes, then king of Persia, and consequently his sovereign. Cyrus was a very young man, but he was a man of a very energetic and accomplished character, and of unbounded ambition. When his father died, it was arranged that Artaxerxes, the older son, should succeed him. Cyrus was extremely unwilling to submit to this supremacy of his brother. His mother was an artful and unprincipled woman, and Cyrus, being the youngest of her children, was her favorite. She encouraged him in his ambitious designs; and so desperate was Cyrus himself in his determination to accomplish them, that it is said he attempted to assassinate his brother on the day of his coronation. His attempt was discovered, and it failed. His brother, however, instead of punishing him for the treason, had the generosity to pardon him, and sent him to his government in Asia Minor. Cyrus immediately turned all his thoughts to the plan of raising an army and making war upon his brother, in order to gain forcible possession of his throne. That he might have a plausible pretext for making the necessary military preparations, he pretended to have a quarrel with one of his neighbors, and wrote, hypocritically, many letters to the king, affecting solicitude for his safety, and asking aid. The king was thus deceived, and made no preparations to resist the force which Cyrus was assembling, not having the remotest suspicion that its destiny was Babylon.