Aimak (or Aimaq) is a term designating Persian-speaking nomadic or semi-nomadic tribes of mixed Iranian and Mongolian stock inhabiting the north and north-west highlands of Afghanistan (immediately to the north of Herat) and in the Khorasan Province of Iran.
They are closely related to the Hazara, and—in varying degrees—to the Tajiks. They live in western Hazarajat in the provinces of Ghor, Farah, Herat, Badghis, Faryab, Jowzjan and Sar-e Pol. The name is Mongolian for tribe (compare Aimag).
They were originally known as chahar or (the four) Eimaks, because there were four principal tribes: the Taimani (the predominating element in the population of Ghor), the Ferozkhoi, the Temuri, and the Jamshidi.
The Chahar Aimaqs are of Turco-Mongolian origin, judging by their physical appearance and their housing (Mongolian-style yurts) but speak a Persian dialect (Dari).
The best estimates of the Aimak population in Afghanistan hover around 1-2 million. The tally is made difficult since, as a consequence of centuries of oppression of the Hazara people in Afghanistan, some Aimagh Hazaras are classified by the state as Tajik, or Persian instead of Aimaks.