Really during any of the major Persian Empires, but I'm most interested in Achaemenid Persia in this case.
I was having a conversation recently about the Biblical book of Esther and in the early part of the story, Mordecai (Esther's Uncle) refuses to kneel to a Persian government official. The Official is offended and tries to kill off all the Jews living in Achaemenid Persia as a result. The traditional Christian interpretation of the passage is that, to Mordecai, kneeling to the Persian official would've been considered idolatry, and so prohibited by his religion. This just doesn't ring true to me, because Persians would have been Zoroastrians at this point, correct? and didn't really ascribe divine nature to their leadership as far as I can remember.
This is a portion of history I know little about, though, so I figured I'd send it to the experts.
Esther 3:2 is the text you appear to have in mind, here’s 3:1-2 in the NET translation:
3:1 Some time later King Ahasuerus promoted Haman the son of Hammedatha, the Agagite, exalting him and setting his position above that of all the officials who were with him. 3:2 As a result, all the king’s servants who were at the king’s gate were bowing and paying homage to Haman, for the king had so commanded. However, Mordecai did not bow, nor did he pay him homage.
I think I would question strongly the “traditional Christian interpretation” that it is because it would be considered idolatry. This is not what you find in most conservative Christian commentaries on the passage. There are very few ancient commentaries/expositions of Esther, but they do not appear to treat it in this sense.
Discussions about the ‘why’ for Mordecai’s refusal discuss a number of matters. Firstly, there is no reason based simply on the fact that he is a Jew. Jews were, and could, bow down to people all the time as an act of honour/respect. The fact that in verse 2, there’s a command to pay homage to Haman, suggests to some that Haman is a fundamentally unlikeable/unliked person for whom it must be commanded, rather than simply expected, that people respect him. I have also seen the suggestion that it is because he is an Agagite, a descendent of the Amelikites, and thus an ancestral enemy. It appears, based on the narrative, that Mordecai isn’t the kind of person just to ‘go along’ with bowing down to Haman, an unworthy character type in the narrative.
As for the Zoroastrian setting. The book is placed in the reign of Ahaseurus/Xerxes, so 486-465 BCE. This would indeed place Zoroastrianism as the state religion. But Haman isn’t so high up that he would have been a candidate for ‘divine nature as leader’ status anyway.