Arachosia is the ancient name of an area that corresponds to the southern part of today 's Afghanistan, around the city of Kandahar. It is directly to the south of Bactria, but is separated from it by the Hindu Kush. The main inhabitants of Arachosia were Pactyans, an ancient Iranian tribe. They were probably the ancestors of today's Pashtuns.

Etymology

Arachosia is derived from Arachotos , a hellenized form of Harachuwati , the Achaemenid Persian name for the Arghandab River , the chief tributary of the Helmand River.