The Persian invasion of Greece between 490-479 BC was the ostensible reason for Alexander’s invasion of the Persian Empire

The Persian invasion of Greece between 490-479 BC was the ostensible reason for Alexander’s invasion of the Persian Empire

. However, other factors made it all but inevitable that he would wage war against it, and they were probably more important to him than Persia’s actions 150 years earlier.

Firstly, military necessity. Alexander had an army that needed to work. If it didn’t it would get restless. But whatever it was doing, the same army also needed paying.

Secondly, economic necessity. The Macedonian economy relied on the plunder of war for its growth. Diplomacy, the projection of power, the ability to bribe all needed money.

Thirdly, political necessity. Without war, Alexander would come under threat from his all sections of his army and court: from the privates who needed to be paid in order simply to live, to his most senior men who expected their king to reward them for their loyalty and work. Without war, the Macedonian economy would collapse, inviting enemies from within and without to try and topple him.

Fourthly, Alexander’s homeric ideals. There was only way to emulate or better Achilles and it was not by sitting on a throne. One might say that Alexander’s faith also led him to war: his desire to outdo Herakles.