The Encyclopædia Iranica is dedicated to the study of Iranian civilization in the Middle East, the Caucasus, Central Asia, and the Indian Subcontinent. It also includes scholarly articles related to the reciprocal influences between Persia and its neighbors, extending from pre-history to the present. The disciplines represented include: anthropology, archaeology, geography, art history, ethnology, sociology, economics, history of religion, philosophy, mysticism, history of science and medicine, Islamic history, botany, zoology, folklore, development of agriculture and industry, political science, international relations, and diplomatic history.

Fascicle 3 of Volume XVII (pp. 225-336) starts with the entry "King of the Benighted--Kingship II. in the Achaemenid Empire" and ends with "Kokand Khanate." The 112 new pages of the Encyclopædia Iranica project reflect the latest developments in the field of Iranian studies.