The Iranian languages form a branch of the Indo-European language family, and are presently spoken in Iran, Afghanistan, Pakistan, as well as in countries in Central and Near East Asia and on the Arabian Peninsula (map). The largest modern Iranian language is Persian (Modern Persian), the official language of Iran and presently one of the most important immigrant languages of Sweden. Among Old and Middle Iranian languages, Avestan, Old Persian, Middle Persian, Parthian, Sogdian, Saka and Bactrian, among others, can be mentioned. Persian has a rich classical literature which goes back to more than 1000 years. The other New Iranian languages have to a various degree, depending on number of speakers and political situation a written literature and a standard written language. All the Iranian languages we have been doing research on so far have rich oral literatures.