Why were the Greeks proud of their victories over the troops of the Persian kings Darius and Xerxes?

In order to understand all the pride that the victorious Greeks felt, we must look to the past. The Greek world is a scattered city. The Greeks did not have a strong army and navy before the victorious war. The Persians, on the contrary, were distinguished by a warlike spirit and powerful defenses. Darius And Xerxes scared almost the entire Ancient World.
Thus, the possibility of rallying and the ultimate victory over the prevailing enemy became the symbol and reason for the military pride of Hellas.