The Taliban ( ' "students"), alternatively spelled Taleban, which refers to itself as the Islamic Emirate of Afghanistan (IEA), is a Sunni Islamic fundamentalist political movement in Afghanistan currently waging war (an insurgency, or jihad) within that country. Since 2016, the Taliban's leader is Mawlawi Hibatullah Akhundzada. 

From 1996 to 2001, the Taliban held power over roughly three quarters of Afghanistan, and enforced there a strict interpretation of Sharia, or Islamic law. The Taliban emerged in 1994 as one of the prominent factions in the Afghan Civil War, and largely consisted of students recently trained in madrassas in Pakistan. Under the leadership of Mohammed Omar, the movement spread throughout most of Afghanistan, sequestering power from the Mujahideen warlords. The Islamic Emirate of Afghanistan was established in 1996 and the Afghan capital transferred to Kandahar. It held control of most of the country until being overthrown by the American-led invasion of Afghanistan in December 2001 following the September 11 attacks. At its peak, formal diplomatic recognition of the Taliban's government was acknowledged by only three nations: Pakistan, Saudi Arabia, and the United Arab Emirates. The group later regrouped as an insurgency movement to fight the American-backed Karzai administration and the NATO-led International Security Assistance Force (ISAF).
what else happened in 2001?
 September 11 attacks