Darius was in the midst of his preparations for a third expedition to Greece, when all his plans were cut short by death. His son and successor, Xerxes I., now became King of Persia in his stead.

The new monarch was not inclined to renew the struggle with the Greeks; but his courtiers and the exiled Greeks who dwelt in his palace so persistently urged him to do it, that he finally consented. Orders were then sent throughout the kingdom to get ready for war, and Xerxes said that he would lead the army himself.