"Balkhī" and "Rūmī" are his "[[Nisba (onomastics)|nisbas]]", meaning, respectively, "from [[Balkh]]" and "from [[Rûm]]" ('Roman,' what European history now calls [[Byzantine]], [[Byzantine Anatolia|Anatolia]]).According to the authoritative Rumi biographer [[Franklin Lewis]] of the [[University of Chicago]], "[t]he Anatolian peninsula which had belonged to the Byzantine, or eastern Roman empire, had only relatively recently been conquered by Muslims and even when it came to be controlled by Turkish Muslim rulers, it was still known to Arabs, Persians and Turks as the geographical area of Rum.