Iranian Architecture. Even after the breakdown of the khilafah that started around 740 and the development of regional styles that began after 900, Iran, as one of the largest cultural regions under Islam, took the lead in establishing an important regional style, even though local dynasties frequently changed, and none ruled the whole of Iran. Eventually, the Iranian area of influence embraced most of the Turco-Iranian world, not only the modern country of Iran, but also Afghanistan and Central Asia to the east and Turkey to the west. Iranian themes also strongly influenced the Muslim architecture of India, which soon, however, took off in its own direction. Likewise, on the west in Anatolia, the rivalry between Ottoman Turkey and Safavid Iran after 1500 helped push the Turks more quickly along the road to their own influential regional tradition. The architecture...