What glorified the Persian state in antiquity?

The Persian state during the history of the Ancient East is the most powerful state and it was glorified for several reasons:
Persia possessed wise and at the same time cruel rulers – Cyrus, Darius, Croesus. The militant people became famous at the same time for a very humane attitude towards the religion and customs of any conquered people;
Persia was the only country that won almost all wars unleashed.
Persia possessed an incredible army, not only in quantity but also in quality. This was the first time in the era of the Ancient East when the army had real combat effectiveness.