After subduing Egypt, he invaded Greece by building a bridge of boats over the Hellesont. He was victorious at Thermopylae and pillaged Athens, but his fleet was destroyed at Salamis (480 B.C.). Xerxes retited to Asia, leaving his army under Mardonius, who was defeated at Plataea (479). He was murdered by one of his soldiers.
He is best known among occultists for his "philosophy of oblivion."
One day when his armed forces were parading before him in review, he wept. One of his generals asked, "Sire, you see before you the greatest army in the world and it is yours. Why do you weep?" The king replied," I weep because I see them marching to oblivion."
Xerxes is mentioned, to as the monarch who summoned his wise men, counselors and advisors, to put before them this problem: "Give me a statement that applies to all men, all things, and all time. On him who provides a suitable answer I will bestow a rich reward."
The counselors, among whom were the best thinkers of the realm, struggled hard and long with the king's question, but none could offer a suitable answer. Finally an old philosopher came forward and offered: "And this, too, shall pass away." The king was pleased and rewarded him.
Thus everything passes away, marching to oblivion. An appropriate modern comparison with the old philosopher's wisdom might be a cliche', "You can't take it with you."
Don't praise luck too highly and don't fear to much, for all they bring to you will come to an end.
Footnote- Dictionary of Astrology by Dal Lee, Warner Books
The Columbia Viking Desk Encyclopedia - Third Edition, The Viking Press