Suleiman the Magnificient restored the boundaries of the Roman Empire by adding Egypt and Africa and the Balkans to the list of Ottoman conquests.
He did what Justinian couldn’t do with far more limited resources in the sixth century. In the fifteenth century, the the two most powerful empires in the world were Islamic: the Ottomans in the West and the Safavids in Persia.
Well put. But for the fifteenth century one shouldn’t forget the Ming Dynasty in China or the Aztecs and Incas in this hemisphere. Point being Islam itself may have been a unifying foundation for the Ottoman and Safavid Empires, but other large empires existed at the same time without it.