"Afghanistan (/æfˈɡænɪstæn, æfˈɡɑːnɪstɑːn/ (About this soundlisten); Pashto/Dari: افغانستان, Pashto: Afġānistān pashto [avɣɒnisˈtɒn, ab-], Dari: Afġānestān [avɣɒnesˈtɒn]), 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 39 million, composed mostly of ethnic Pashtuns, Tajiks, Hazaras, and Uzbeks.
The history of Afghanistan (Persian: تاریخ افغانستان, Tārīkh e Afġānistān; Pashto: د افغانستان تاريخ,Da Afġānistān Tārīkh) as a state began in 1747 with its establishment by Ahmad Shah Durrani. The written recorded history of the land presently constituting Afghanistan can be traced back to around 500 BCE when the area was under the Achaemenid Empire, although evidence indicates that an advanced degree of urbanized culture has existed in the land since between 3000 and 2000 BCE. Bactria dates back to 2500 BC. The Indus Valley Civilisation stretched up to large parts of Afghanistan in the north. Alexander the Great and his Macedonian army arrived at what is now Afghanistan in 330 BCE after the fall of the Achaemenid Empire during the Battle of Gaugamela. Since then, many empires have risen from Afghanistan, including the Greco-Bactrians, Kushans, Hephthalites, Saffarids, Samanids, Ghaznavids, Ghorids, Khaljis, Timurids, Mughals, Hotakis and Durranis.
Afghanistan (meaning "land of the Afghans" or "Afghan land" has been a strategically important location throughout history. The land served as "a gateway to India, impinging on the ancient Silk Road, which carried trade from the Mediterranean to China". Sitting on many trade and migration routes, Afghanistan may be called the 'Central Asian roundabout' since routes converge from the Middle East, from the Indus Valley through the passes over the Hindu Kush, from the Far East via the Tarim Basin, and from the adjacent Eurasian Steppe.
The Iranian languages were developed by one branch of these people; the Pashto language spoken today in Afghanistan by the ethnic Afghans, Pashtuns is one of the Eastern Iranian languages. Elena E. Kuz'mina argues that the tents of Iranian-speaking nomads of Afghanistan developed from the light surface houses of the Eurasian steppe belt in the Bronze Age.
The Arab invasions influenced the culture of Afghanistan, and its pre-Islamic period of Zoroastrian, Macedonian, Buddhist and Hindu past has long vanished.
Mirwais Hotak followed by Ahmad Shah Durrani unified Afghan tribes and founded the last Afghan Empire in the early 18th century CE. Afghanistan is inhabited by many and diverse peoples: the Pashtuns, Tajiks, Hazaras, Uzbeks, Turkmen, Aimak, Pashayi, Baloch, Pamiris, Nuristanis, and others."
(from Wikipedia)
Afghanistan's Islam From Conversion to the Taliban