The Achaemenid Empire left a lasting impression on the heritage and cultural identity of Asia, Europe, and the Middle East, and influenced the development and structure of future empires. In fact, the Greeks, and later on the Romans, adopted the best features of the Persian method of governing an empire. The Persian model of governance was particularly formative in the expansion and maintenance of the Abbasid Caliphate, whose rule is widely considered the period of the 'Islamic Golden Age'. Like the ancient Persians, the Abbasid dynasty centered their vast empire in Mesopotamia (at the newly founded cities of Baghdad and Samarra, close to the historical site of Babylon), derived much of their support from Persian aristocracy and heavily incorporated the Persian language and architecture into Islamic culture. The Achaemenid Empire is noted in Western history as the antagonist of the Greek city-states during the Greco-Persian Wars and for the emancipation of the Jewish exiles in Babylon. The historical mark of the empire went far beyond its territorial and military influences and included cultural, social, technological and religious influences as well. For example, many Athenians adopted Achaemenid customs in their daily lives in a reciprocal cultural exchange, some being employed by or allied to the Persian kings. The impact of Cyrus's edict is mentioned in Judeo-Christian texts, and the empire was instrumental in the spread of Zoroastrianism as far east as China. The empire also set the tone for the politics, heritage and history of Iran (also known as Persia). Historian Arnold Toynbee regarded Abbasid society as a "reintegration" or "reincarnation" of Achaemenid society, as the synthesis of Persian, Turkic and Islamic modes of governance and knowledge allowed for the spread of Persianate culture over a wide swath of Eurasia through the Turkic-origin Seljuq, Ottoman, Safavid and Mughal empires.