Re: Who exactly is Zulqurnain, as mentioned in Quran?
I think you're onto something there ume-zafeerah.
I too have my doubts about it being Alexander the Great. Wasn't he Greek? and Greeks/Romans were polytheists.
Cryus is a zoroastrian, which according to what i have read was based on Tauheed. Though the way of worship might be different than how muslims pray today.
Also the two horns could mean two lands, Persia was divided into two power which were constantly at war with each other. Lydia and Media, and Cyrus united the two.