The Encyclopædia Iranica is concerned with all aspects of Iranian history and culture as well as all Iranian languages and literatures. The geographical focus is on Iran and Afghanistan, as well as parts of the Middle East, the Caucasus, Central Asia, and the Indian subcontinent; however, relations between these societies, their direct neighbors, and other parts of the world are included. The time span covered extends from the dawn of prehistory to the present, but biographies of living persons are not included.