the country's classical eras, particularly with the adoption of details from the ancient monuments in the Achaemenid capitals Persepolis and Pasargadae and the Sasanian capital Ctesiphon. Fars, corresponding to the ancient province of Persia, with its modern capital Shiraz, became a center of interest, particularly during the annual international Shiraz Arts Festival and the 2,500th anniversary of the founding of the Persian Empire. The Pahlavi rulers modernized Iran, and ruled it until the 1979 Revolution. Anthropology In modern Iran, the Persians make up the majority of the population. They are native speakers of the modern dialects of Persian, which serves as the country's official language. Persian language The Persian language belongs to the western group of the Iranian branch of the Indo-European language family. Modern Persian is classified as a continuation of Middle Persian, the official religious and literary language of the Sasanian Empire, itself a continuation of Old Persian, which was used by the time of the Achaemenid Empire. Old Persian is one of the oldest Indo-European languages attested in original text. Samples of Old Persian have been discovered in present-day Iran, Armenia, Egypt, Iraq, Romania (Gherla), and Turkey. The oldest attested text written in Old Persian is from the Behistun Inscription, a multilingual inscription from the time of Achaemenid ruler Darius the Great carved on a cliff in western Iran. Related groups There are several ethnic groups and communities that are either ethnically or linguistically related to the Persian people, living predominantly in Iran, and also within Afghanistan, Tajikistan, Uzbekistan, the Caucasus, Turkey, Iraq, and the Arab states of the Persian Gulf. The Tajiks are a people native to Tajikistan, Afghanistan, and Uzbekistan who speak Persian in a variety of dialects. The Tajiks of Tajikistan and Uzbekistan are native speakers of Tajik, which is the official language of Tajikistan, and those in Afghanistan speak Dari, one of the two official languages of Afghanistan. The Tat people, an Iranian people native to the Caucasus (primarily living in the Republic of Azerbaijan and the Russian republic of Dagestan), speak a language (Tat language) that is closely related to Persian. The origin of the Tat people is traced to an Iranian-speaking population that was resettled in the Caucasus by the time of the Sasanian Empire. The Lurs, an ethnic Iranian people native to western Iran, are often associated with the Persians and the Kurds. They speak various dialects of the Luri