Herodotus (c 484 – c 425 BC) attests that the Gandarian mercenaries (i.e. "Gandharans/Kambojans" of Gandari Strapy of Achaemenids) from the 20th strapy of the Achaemenids were recruited in the army of emperor Xerxes I (486–465 BC), which he led against the Hellas. Similarly, the "men of the Mountain Land " from north of Kabul-River equivalent to medieval Kohistan (Pakistan), figure in the army of Darius III against Alexander at Arbela, providing a cavalry force and 15 elephants. This obviously refers to Kamboja cavalry south of Hindukush.