Muluk Al Tawaif

The "Muluk al-Tawaif" (Party Kings), according to Abu Sahl ibn Nawbakht as transmitted by Ibn al-Nadim: after "the deed of Alexander", learning was studied in Iraq, people became partisan and divided, and each faction had its own king, so they were called the Party Kings. ²

He says that the kings of the Romans later gathered under one king, after the division that had been among them. ²