From Gene Expression:

There are certain things which are sacred, certain lines you don’t cross. … I was thinking about [this] a few months ago when I read Rome & Jerusalem: A Clash of Ancient Civilizations and God’s Rule – Government and Islam. You see, the ancient Romans and Muslims did not have kings. Kings were tyrants, and the early Roman and Islamic polities rejected such tyranny on principle. So of course, instead of kings, the Roman Empire was headed by an emperor, while the Muslims had caliphs. Get it? When Augustus defeated Mark Antony and Cleopatra the official narrative was that the doughty republican traditions of Rome had bested once more the oriental despotism of the Hellenistic world, with their Greek kings and queens. Similarly, the righteous AbbasidsUmayyads. In its place they established a genuine Islamic state which was guided by the traditions of the community as opposed to profane naked autocracy. Right….

As you can see here, the extent of the self-deception and semantic delusion is really humorous. Now, it is true that the early emperors of Rome tended to keep up the illusion that they were simply stewards of the Roman Republic with some verisimilitude. Augustus’ shtick was that his was a restorationist project; he was no dictator or king, just the First Citizen. Similarly, the early Abbasids were ostensibly bringing the vision of the Islamic community to its true fulfillment (especially the Shia party), whereas the Umayyads had been worldly Arab tribalists more in keeping with the values of the jahiliya. … Muslim soldiers were enraged and shocked when the conqueror of Spain allowed his Visigothic wife to convince him to don a crown and so indicate kingship; they accused him of becoming a Christian.