Little known outside academic circles before 2001, the Taliban became the focus of America's war on terror after the Sept. 11, 2001 terrorist attacks when the group refused to hand over accused terrorist and 9/11 mastermind Osama bin Laden and members of his al-Qaida network.

Before then, the Taliban ruled Afghanistan under strict Islamic law.

Under the group's rule, government forces in the Ministry for the Promotion of Virtue and Prevention of Vice patrolled the streets enforcing a conservative interpretation of Islamic law. The punishments were severe: thieves had their arms or legs amputated, adulterers were stoned to death and drinking liquor resulted in lashings.

Under the Taliban regime, girls were forced out of school, and women were banned from holding jobs, required to wear full-body burqas and were rarely permitted to leave their homes.

Laws required men to grow their beards and prohibited Western-style clothing. Playing games, sports, flying kites, listening to music or watching TV were all forbidden and punishable.

In 1994, when the Taliban came to power, the Afghan people saw the group as peacemakers who promised a respite from years of fighting during Mujahadeen rule. But the swing from purveyor of peace to hard-line Islamist rule was not welcome by many and soon led to a backlash from the international community.

The United Nations and nongovernmental organizations, including Amnesty International, Human Rights Watch and Physicians for Human Rights, accused the Taliban regime of widespread human rights abuses, especially concerning religious freedom and women's rights.

On Oct. 7, 2001, following the 9/11 attacks, the United States, backed by a coalition of international forces, entered Afghanistan with the aim of toppling the Taliban government and capturing bin Laden.

After the government fell, the coalition hunted for Taliban fighters and offered a $50 million reward for capturing bin Laden. But the terrain -- extremely mountainous and passable only by foot -- made the task difficult, and many Taliban fighters fled and found a haven in the Pashtun tribal areas of Pakistan. There they could regroup, rearm their militias, and recruit more fighters from the large Afghan refugee populations and madrassas, or Islamic schools.

To build their support among Afghanistan's impoverished population, the Taliban capitalized on economic frustrations by outbidding coalition offers to recruit new fighters. The group also offered security that newly installed President Hamid Karzai's government failed to provide, a repeat of the promises it had made when it first rose to power in 1994.

Between 2001 and 2006, U.S. and North Atlantic Treaty Organization, or NATO, troops remained in Afghanistan, but their presence was light and they left a power vacuum in the south. This, coupled with frustrations about the central government's failure to follow through with promises of development, created an environment for the Taliban to regain its influence.

"People don't really like the Taliban but they don't feel like the government can provide them with anything," said Sam Zarifi of Human Rights Watch.

According to Zarifi, the Taliban offer an alternative to foreign influence in the region. "They are angry and frustrated with the heavy handed tactics by the U.S. and NATO forces."

The Taliban formed as a group of young Koranic students -- "talib" means student in Arabic -- from madrassas in the Afghan refugee camps of Pakistan. They were predominantly Pashtun -- though other ethnic groups were included -- and exclusively Sunni Muslim.

Amir Mullah Mohammed Omar, called the "Commander of the Faithful," served as the movement's leader. Members united under the mission to restore peace after years of war and lawlessness, disarm the population and to enforce Sharia, or Islamic law on the people of Afghanistan, according to Ahmed Rashid, author of "Taliban."

The movement conquered Kandahar in the winter of 1994 and swept southern Afghanistan before capturing Kabul in September 1996. Once in power, the Taliban provided a haven for bin Laden and al-Qaida, who in return gave financial and political support.

In 2001, the Taliban received widespread condemnation from the United Nations and governments around the world for destroying two Buddha statues thought to be the world's tallest in the cliffs of Bamiyan claiming the statues were an affront to Islam.

The Taliban operates in a shura structure where decisions are made among a council with bases in Quetta, Baluchistan and Warziristan in Pakistan. In 2006, elements of the old Taliban structure still existed with Mullah Omar, the Taliban's one-eyed leader in charge, and Mullah Dadullah as a commander and spokesman.

The broader anti-government movement is a combination of the old school Taliban, smaller groups that operate independently but are ideologically aligned, and elements of al-Qaida.

Within this loose and fragmented network, Mullah Omar and bin Laden continue to play spiritual and philosophical leadership roles, but the operational tactics and actual terrorist activities are organized and carried out by smaller groups.

Though the exact link between al-Qaida and the Taliban is hard to define, there is some evidence that the Taliban is receiving training and material from insurgents in Iraq, according to Zarifi.

The Taliban form the backbone of an anti-government insurgency that in 2006 began regaining power in Afghanistan's southern provinces of Helmand, Oruzgan and Kandahar and across the border in Pakistan's Baluchistan and North West Frontier Provinces. The group once again has a deep influence on civilian life, and as its political and military power increases, many of the human rights advances made after its fall have been rolled back.

The group's primary goal remains the same: to reinstate a strict Islamic-oriented government in Afghanistan. Its tactics, however, have shifted with the influence of other terrorist organizations, notably al-Qaida.

After the U.S. invasion, the Taliban, al-Qaida, warlords, militant groups in Pakistan and drug producers became intertwined, providing all groups with more financial support, recruitment opportunities and training.

Since its resurgence, the Taliban has adopted new guerilla tactics such as suicide bombings -- formerly a rare occurrence in Afghanistan -- and the application of explosive devices used successfully in Iraq. It is unclear if Taliban fighters were taught these tactics or are emulating what they see from al-Qaida in Iraq. It also has amassed ample supplies of explosives, some smuggled from Russia, Iran or Eastern Europe that are used for improvised explosive devices and suicide bombs.

But while al-Qaida works to spread its global jihad across the Middle East, central Asia and the Caucasus, the Taliban -- using funds from private individuals and possibly al-Qaida members sympathetic to its cause, according to Greg Sullivan, a spokesman for the State Department's Near East Asian Affairs Bureau -- is focused solely on returning to power in Afghanistan.

-- By Anna Shoup, Online NewsHour