Afghanistan (, also pronounced /æv'?æn?stæn, æv':n?st?:n/; Pashto/Dari: , Pashto: Afnist?n [avnis't?n, ab-], Dari: Afnest?n [avnes't?n]), officially the Islamic Republic of Afghanistan, is a landlocked country at the crossroads of Central and South Asia. Afghanistan is bordered by Pakistan to the east and south; Iran to the west; Turkmenistan, Uzbekistan, and Tajikistan to the north; and China to the northeast. Occupying 652,000 square kilometers (252,000 sq mi), it is a mountainous country with plains in the north and southwest. Kabul is the capital and largest city. The population is around 32 million, composed mostly of ethnic Pashtuns, Tajiks, Hazaras, and Uzbeks.
Humans lived in what is now Afghanistan at least 50,000 years ago. Settled life emerged in the region 9,000 years ago, evolving gradually into the Indus civilization (Shortugai site), the Oxus civilization (Dashlyji site), and the Helmand civilization (Mundigak site) of the 3rd millennium BCE. Indo-Aryans migrated through Bactria-Margiana area to Gandhara, followed by the rise of the Iron Age Yaz I culture (ca. 1500-1100 BCE), which has been closely associated with the culture depicted in the Avesta, the ancient religious texts of Zoroastrianism. The region, then known as "Ariana", fell to Achaemenid Persians in the 6th century BCE, who conquered the areas to their east as far as the Indus River. Alexander the Great invaded the region in the 4th century BCE, who married Roxana in Bactria before his Kabul Valley campaign, where he faced resistance from Aspasioi and Assakan tribes. The Greco-Bactrian Kingdom became the eastern end of the Hellenistic world. Following the conquest by Mauryan Indians, Buddhism and Hinduism flourished in the region for centuries. The Kushan emperor Kanishka, who ruled from his twin capitals of Kapi?i and Puru?apura, played an important role in the spread of Mahayana Buddhism to China and Central Asia. Various other Buddhist and Hindu dynasties also ruled the region, including the Saka, Kidarite, Hephthalite, Alkhon, Nezak, Zunbil, Turk Shahi, and Hindu Shahi. (Full article...)