HELMAND RIVER (Av. Haētumant; modern usage, Hirmand, Halmand), the border river of Afghanistan and Persia. It originates in the mountains in the Hazārajāt (q.v) and flows into the Sistān in southeastern Persia and finally drains into the Hāmun Lake (q.v.).

i. Geography.

ii. In Zoroastrian tradition.

iii. In the medieval period.

iv. In the late 19th and 20th centuries.