Tabaristan or Tabarestan (Persian: طبرستان, romanized: Ṭabarestān, or Mazanderani: تبرستون, romanized: Tabarestun, ultimately from Middle Persian: 
, Tapur(i)stān), was a mountainous region located on the Caspian coast of northern Iran. It corresponded to the present-day province of Mazandaran, which became the predominant name of the area from the 11th-century onwards.[1]