"Around the year 700 al-Malik ordered that public servants across the Umayyad world should use one language only: Arabic. The commonest tongues used by the non-Arabs who made up the vast majority of the caliphate’s population were Greek and Persian. Al-Malik made no provision against people speaking them as they pleased—but he decreed that they could no longer do so while working for him. At a stroke, the Christians, Jews, and Zoroastrians who had found gainful employment as scribes, middle managers, and government bureaucrats were faced with a stark choice. Unless they knew or very quickly learned Arabic, they were out of a job. This simple administrative change was in fact a moment of juddering cultural importance in the history of the Islamic world—for it ensured that there would be an Islamic world in perpetuity, rather than a short-lived federation of former Roman and Persian territories ruled over by a thin monotheistic elite. As we saw in chapter one, the Roman Empire in its pomp had been bound together over millions of square miles in part because Latin was a common language of cultural discourse as well as base communication. Al-Malik now set Arabic on a similar path. By enforcing its use of a universal tongue across the caliphate, he transformed it into a global language of record and inquiry."