The Encyclopaedia Iranica covers topics related not only to modern Persia but also to the whole Iranian cultural world, including in-depth treatment of Tajikistan, Afghanistan, and Kurdistan. Articles also delve into historical and cultural relations with nations such as Egypt, Britain, India, and China. Spanning ancient, medieval, and modern times, the Encyclopaedia reveals the geographical, archaeological, cultural, religious, governmental, and biographical details that have left their mark on Iranian society.