On Sunday, the Taliban militant group entered the Afghan capital city Kabul, following a week of rapid territorial gains from retreating government forces.
Here are some key facts about the Taliban's history and ideology:
The Taliban, which means "students" in the Pashto language, emerged in 1994 around the southern Afghan city of Kandahar. The group was one of the factions fighting a civil war for control of the country following the withdrawal of the Soviet Union and subsequent collapse of the government.
It originally drew members from so-called "mujahideen" fighters who, with support from the United States, repelled Soviet forces in the 1980s.
Within the space of two years, the Taliban had gained sole control over most of the country, proclaiming a religious emirate in 1996 with a harsh interpretation of Islamic law. Other mujahideen groups retreated to the north of the country.
Following the Sept. 11, 2001 attacks in the United States by al-Qaida, U.S.-backed forces in the north swept into Kabul in November under the cover of heavy U.S. airstrikes.
The Taliban melted away into remote areas, where it began a 20-year-long insurgency against the Afghan government and its Western allies.
The Taliban's founder and original leader was Mullah Mohammad Omar, who went into hiding after the Taliban was toppled. So secretive were his whereabouts that his death, in 2013, was only confirmed two years later by his son.
During its five years in power, the Taliban enforced a strict version of of their interpretation of Shariah. Women were predominantly barred from working or studying, and were confined to their homes unless accompanied by a male guardian.
Public executions and floggings were common, Western films and books were banned and cultural artefacts were destroyed.
Opponents and Western countries accuse the Taliban of wanting to return to this style of governance in the areas it already controls – a claim the group denies.
Only four countries, including neighbor Pakistan, recognized the Taliban government when it was in power.
The vast majority of other countries, along with the United Nations, instead recognized a group holding provinces to the north of Kabul as the rightful government-in-waiting.
The United States and the United Nations imposed sanctions on the Taliban, and most countries show little sign they will recognize the group diplomatically.
U.S. Secretary of State Antony Blinken said earlier this month Afghanistan risks becoming a pariah state if the Taliban takes power and commits atrocities.
Other countries such as China have begun cautiously signaling they may recognize the Taliban as a legitimate regime.
