By Rahimullah Yusufzai BBC correspondent in Peshawar , Octiber 5, 2005
Four years after losing power in the country, the Taleban are making their presence felt by launching guerrilla operations against the US-led coalition forces, killing aid workers and kidnapping foreigners involved in reconstruction work.
Taleban forces as they fled Kabul
Parts of eastern and southern Afghanistan have been rendered more and more insecure due to the increasingly daring Taleban attacks.
The Taleban first came to prominence in the autumn of 1994.
Their leader was a village clergyman Mullah Mohammad Omar, who lost his right eye fighting the occupying forces of the Soviet Union in the 1980s.
Their target was the feuding warlords known as the mujahideen who had forced the Soviet troops out of the country.
The Taleban's promise was to restore peace and security and enforce Sharia, or Islamic law, once in power.
Afghans, weary of the mujahideen's excesses and infighting, generally welcomed the Taleban.
Their early popularity was largely due to their success in stamping out corruption, curbing lawlessness and making the roads and the areas under their control safe for commerce to flourish.
From their birthplace in the province of Kandahar in south-western Afghanistan, the Taleban quickly extended their influence.
They captured the province of Herat, bordering Iran, in September 1995.
Exactly one year later, they captured the Afghan capital, Kabul, after overthrowing the regime of President Burhanuddin Rabbani and his defence minister, Ahmed Shah Masood.
By 1998, they were in control of almost 90% of Afghanistan.
The circumstances of the Taleban's emergence remained the centre of controversial debate.
Despite repeated denials, Pakistan is seen as the architect of the Taleban enterprise.
Wreckage from a recent attack in Kandahar blamed on the Taleban
Suspicions arose early on when the Taleban went to the rescue of a Pakistani convoy stranded in Kandahar following attacks and looting by rival mujahideen groups.
Many of the Afghans who joined the Taleban were educated in madrassas (religious schools) in Pakistan.
Pakistan was also one of only three countries, along with Saudi Arabia and the United Arab Emirates (UAE), which recognised the Taleban regime.
It was also the last country to break diplomatic ties with the Taleban.
The US put Pakistan under pressure to do so after the 11 September, 2001, attacks in New York and Washington.
The Taleban were overwhelmingly Pashtun, the ethnic group that forms the majority of Afghanistan's diverse population and also inhabits the North-West Frontier Province (NWFP) and Balochistan in neighbouring Pakistan.
Even now, the resurgent Taleban draw considerable sympathy from fellow Pashtuns in Pakistan.
Some of their fugitive leaders are able to find refuge across the long and porous border in NWFP and Balochistan.
Once in power, the Taleban set up an authoritarian administration that tolerated no opposition to their hardline policies.
Differences on strategy and Mullah Omar's authoritarian style have prompted some Taleban to quit the movement or become inactive
Islamic punishments, such as public executions of convicted murderers and amputations of those charged with thefts, were introduced.
Television, music and cinema were banned after being adjudged as frivolities.
Girls aged 10 and above were forbidden from going to school - working women were ordered to stay at home.
Men were required to grow beards and women had to wear the burqa.
The Taleban's religious police earned notoriety as they tried to implement these restrictions.
Taleban policies, particularly those concerning human and women's rights, also brought them into conflict with the international community.
But what was to bring much greater conflict was the Taleban's role as host to Osama Bin Laden and his al-Qaeda movement.
Mullah Omar's precise whereabouts are still unknown
The August 1998 bombings of the US embassies in Kenya and Tanzania that left more than 225 people dead prompted Washington to present the Taleban with a difficult choice.
They were required to expel Bin Laden, who the US held responsible for those bombings and other attacks, or face the consequences.
When the Taleban refused to hand over their Saudi-born guest, US President Bill Clinton ordered a missile attack on a bin Laden camp in southern Afghanistan.
As further punishment, the US persuaded the UN Security Council to impose sanctions on Taleban-ruled Afghanistan in 1999.
Harsher UN sanctions were put in place in 2001 in another effort to force the Taleban to deliver bin Laden.
The sanctions, and the denial of Afghanistan's seat in the UN to the Taleban, increased the political and diplomatic isolation of their regime.
It also prompted it to pursue a more isolationist and fundamentalist agenda.
For example, the Taleban went ahead with the destruction of the priceless Bamiyan Buddha statues carved out of a mountain cliff in central Afghanistan, despite international outrage.
The events of 11 September signalled the beginning of the end for the Taleban's control of Afghanistan.
The US reiterated its demand that the Taleban hand over bin Laden to face trial for masterminding the attacks on US soil.
But again, the Taleban defended bin Laden and refused to expel him.
On October 7, 2001, a US-led coalition intervened militarily in Afghanistan and by the first week of December the Taleban regime had collapsed.
Mullah Omar and most of the other senior Taleban leaders, along with Bin Laden and some of his senior al-Qaeda associates, survived the American onslaught.
Mullah Omar and his comrades have evaded capture despite one of the largest manhunts in the world and are believed to be guiding the resurgent Taleban.
The Taleban retreat enabled them to limit their human and material losses.
However, differences on strategy and Mullah Omar's authoritarian style have prompted some Taleban to quit the movement or become inactive.