The Pashtun people ( Pax̌tānə; Pakhtun or Pukhtun in northern dialects), also known historically as Afghān (Persian/Arabic: ) or Paṭhān (Hindi: ; Urdu: ), are an Indo-European ethnic group from the subgroup of Eastern Iranians, native to northwestern Pakistan and Afghanistan, who speak the Pashto language. The Pashtuns are traditionally characterised by the practice of Pashtunwali, which is a self-governing tribal system of ethics guiding individual and communal conduct. Often characterised as a warrior and martial race, their history is mostly spread amongst various countries of South and Central Asia, centred on their traditional seat of power in medieval Afghanistan. Many members have left their native land to other parts of the world where they achieved international fame. The Pashtuns are the world’s largest (patriarchal) segmentary lineage social group. According to Ethnologue, the total population of the group is estimated to be around 50 million but an accurate count remains elusive due to the lack of an official census in Afghanistan since 1979. Estimates of the number of Pashtun tribes range from about 350 to over 400.