The region served as a satrapy (province) of the Median Empire, a sub-province of the Achaemenid Empire, and a province within
its successors, the Seleucid, Arsacid and Sasanian empires. Hyrcania bordered Parthia to the east (later known as Abarshahr),
Dihistan to the north, Media to the south and Mardia to the west. After the fall of the Sasanian Empire in 651 AD, Hyrcania
was known as Tabaristan.