Persian is an important language today in a number of countries of west, south and central Asia. But its status in each is different. In Iran its unique status as the only official or national language continues to be jealously guarded, even though half—probably more—of the population use a different language (mainly Azari/Azeri Turkish) at home, and on the streets, though not in formal public situations, and not in writing. Attempts to broach this exclusive status of Persian in Iran have increased in recent decades, but are still relatively minor. Persian (called tajiki) is also the official language of Tajikistan, but here it shares that status informally with Russian, while in the west of the country Uzbek is also widely used and in the more isolated eastern part of the country other local Iranian languages are now dominant. In Afghanistan, although Persian (officially renamed dari in 1964, but still commonly called farsi) is the official language, the national language is Pashto, and there is no official restriction on the use of other languages (see discussion by Nawid in this volume). Persian also continues to be spoken in some of the northern and western parts of Pakistan and the southern littoral of the Persian Gulf. Meanwhile, for most people in Pakistan, Bangladesh and India, for reasons that are explained later, Persian is informally recognized as a classical language. In the other countries of the region—Turkey, the Caucasus, the Persian Gulf and the other Central Asian republics—somewhat negative, discriminatory attitudes are found with regard to Persian. This situation is a consequence of the nationalisms that have emerged over the past fifty years or so. This unusual combination of vast geographical distribution and country-by-country variation can be explained only by detailed reference to the history of the language. Persian makes an interesting historical case study, because it includes in a somewhat exaggerated form a number of features that are found in other modern languages that have long textual records—features which throw a shadow of the continuing development of language policies in all these countries, and may illuminate some of the less tangible factors behind language policy in general.