During its continuance a fierce iconoclastic spirit animated the princes of the Empire, who took every opportunity of showing their hatred and contempt for the idolatries of the neighboring nations, burning temples, confiscating or destroying images, scourging or slaying idolatrous priests, putting a stop to festivals, disturbing tombs, smiting with the sword animals believed to be divine incarnations.

Within their own dominions the fear of stirring up religious wars compelled them to be moderately tolerant, unless it were after rebellion, when a province lay at their mercy; but when they invaded foreign countries, they were wont to exhibit in the most open and striking way their aversion to materialistic religions.

In Greece, during the great invasion, they burned every temple that they came near; in Egypt, on their first attack, they outraged every religious feeling of the people.
It was during this time of comparative purity, when the anti-idolatrous spirit was in full force, that a religious sympathy seems to have drawn together the two nations of the Persians and the Jews.

Cyrus evidently identified Jehovah with Ormazd, and, accepting as a divine command the prophecy of Isaiah, undertook to rebuild their temple for a people who, like his own, allowed no image of God to defile the sanctuary.

Darius, similarly, encouraged the completion of the work, after it had been interrupted by the troubles which followed the death of Cambyses.