Who exactly is Zulqurnain, as mentioned in Quran?

Doesnt seem like he did.
But then again not all the people mentioned in Quran are Muslim as we call them.
A lot of mentions are about time that predates Quran, all the way till Adam.
Waisy to hadrat Eisa never called himself Muslim either.

The story of Alexandar the great is from 336-323 BC. So if anything he would’ve been a jew.