(Mazandaran) a historical region in Iran between Gilan in the west and Khorasan in the east; under the present administrative division, it is an ostan. Area, 47,400 sq km. Population, 2,300,000 (1971-72). Sari, the capital of Mazanderan, is the administrative center. Important cities are Shahi, Behshahr, Gorgan, Babol, Bandar-e Shah, and Amol.
In sources of the ninth through 12th centuries, Mazanderan is referred to as Tabaristan; the name “Mazanderan” has existed since the 13th century. Under the Sassanids, the region was known as an independent possession of the Mazanderan rulers. As part of the Arabian Caliphate, during the reign of the Samanids, Seljuks, and Mongols, local Mazanderan dynasties still ruled in Mazanderan. At the end of the 16th century, under Shah Abbas I (ruled 1587-1629), the local dynasty in Mazanderan was liquidated and Mazanderan was made part of the Safawid state.
Mazanderan was one of the regions of Iran where a democratic movement arose in 1920-21. Between 1946 and 1951, in several cities of Mazanderan, including Babol and Sari, there were mass rallies and demonstrations against the Anglo-Iranian Oil Company.