Alexander answered the proposition of the Persian king in a stern mood, fully conscious of his strength. His letter to Darius, which has been preserved, is a document that speaks in no uncertain tone. “Your ancestors invaded Macedonia and the rest of Greece, and without provocation inflicted wrongs upon us. I was appointed leader of the Greeks and crossed over into Asia for the purpose of avenging those wrongs; for ye were the first aggressors. In the next place ye assisted the people of Perinthus, who were offenders against my father, and Ochus sent a force into Thrace, which was part of our empire. Further, the conspirators who slew my father were suborned by you, as ye yourselves boasted in your letters. Thou with the help of Bagoas didst murder Arses (son of Ochus) and seize the throne unjustly and contrary to the law of the Persians, and then thou didst write improper letters regarding me to the Greeks, to incite them to war against me, and didst send to the Lacedæmonians and other of the Greeks, for the same purpose, sums of money (whereof none of the other cities partook but only the Lacedæmonians); and these emissaries corrupted my friends and tried to dissolve the peace which I had brought about in Greece. Wherefore I marched forth against thee who wert the aggressor in general. I have overcome in battle first thy generals and satraps, and now thyself and thine host, and possess thy land through the grace of the gods. Those who fought on thy side and were not slain but took refuge with me, are under my protection and are glad to be with me and will fight with me henceforward. I am lord of all Asia, and therefore do thou come to me. If thou art afraid of being evilly entreated, send some of thy friends to receive sufficient guaranties. Thou hast only to come to me to ask and receive thy mother and children, and whatsoever else thou mayest desire. And for the future whenever thou sendest, send to me as to the Great King of Asia, and do not write as to an equal, but tell me whatever thy need be, as to one who is lord of all that is thine. Otherwise I shall deal with thee as an offender. But if thou disputest the kingdom, then wait and fight for it again and do not flee; for I will march against thee, wherever thou mayest be.” Darius now set about collecting another army and made no more peace proposals. He gathered the fragments of the force that had been beaten at Issus, and to this were added contingents drawn from all the furthermost parts of his empire still in his hands. The army so formed was almost exclusively Asiatic, for of Greek mercenaries there were only the soldiers, a few thousand all told, who had followed him in his flight. No others could now be secured. Darius’ new plan was to await the approach of Alexander on the plains of Assyria, where the Persian cavalry could be used with most effect.