Drawn mostly from Afghanistan's majority Pashtun ethnic group, the original leadership of the Taliban chose the name for the movement because it denotes students of Islamic theology.
Barnett Rubin, a leading expert on Afghanistan and director of New York University's Center on International Cooperation, explains that the youngest of the original Taliban were Afghans who were born or grew up in refugee camps in Pakistan during the Soviet occupation of Afghanistan.
"The Taliban, of course, are an indigenous Afghan or Afghan-Pakistani organization which really grew up during the 20 years that there were millions of Afghan refugees in Pakistan -- where the only education available for them was in madrasahs, often in [Pakistan's] tribal territories," Rubin says. "It recruited from those people and it really had a local agenda."
But the Taliban's supreme spiritual leader, Mullah Mohammad Omar, is much older. He was born sometime around 1959 in the village of Nodeh near Kandahar, into a family of poor, landless members of the Hotak tribe -- one of many sub-tribes and clans within the Ghilzai branch of Pashtuns.
Omar became a village mullah in the Mewand district of Kandahar Province. He also fought against Afghan President Najibullah's communist regime from 1989 to 1992 as a member of Mohammad Yunus Khales' Hizb-e Islami -- a mujahedin group headquartered in Pakistan that had received Western aid and support during the 1980s that was channeled through elements of Pakistan's Interservices Intelligence (ISI).
Significantly, Mullah Omar's Ghilzai tribe is a historical adversary of another important ethnic-Pashtun group -- the Durrani tribe of Afghan President Hamid Karzai. Religion To Politics
Antonio Giustozzi is a research fellow at the London School of Economics who has studied the evolution of the Taliban since the September 11, 2001, terrorist attacks in the United States. Giustozzi tells RFE/RL it would be wrong to consider today's Taliban a single ethnic group or tribe.
"I would basically describe it as a religious network which turned into a political movement," Giustozzi says. "And then they started expanding -- co-opting other religious networks, and then gradually going beyond those religious networks to start forming alliances with local communities or local power players."
He explains that the Taliban lacks a strong organizational structure and is essentially still a network based on personal relations between the leadership and people at the local level.
"Mullah Omar is not an authoritative leader," Giustozzi says. "He is more like a broker among different members of the leadership who may have differences over issues of how to fight the war or whether to negotiate or not. So in a sense, it is modeled from their experience as clerics."
In his recently published book, "Koran, Kalashnikov And Laptop: The Neo Taliban Insurgency In Afghanistan," Giustozzi describes how the Taliban leadership has recently embraced new strategies and technologies, including computers and suicide bombings. Giustozzi's book also describes how the Taliban has reorganized and adapted to changing political conditions in Afghanistan since 2002.
"Of course, the top leaders are people who have been with the Taliban for a long, long time. So in that sense, the very top leaders are still the same," Giustozzi explains. "What is new is that they are trying to incorporate new constituencies and, therefore, represent different tribes and communities. So as their constituencies change, they also adapt to those constituencies."
He says the original Taliban were largely Ghilzai, from the Ghilzai confederation, while in 2003 and 2004, the majority of the leadership were actually Durannis.
"We actually are not totally sure today what the composition of their leadership is," Giustozzi adds. "But one can detect an attempt to represent the different constituencies at the level of the leadership." Revised Goals
Giustozzi also notes that the goals claimed by the Taliban have changed, along with its fighting tactics, as the security and political situation in the country has evolved.
"Today, the Taliban are essentially a guerrilla movement, whereas in the 1990s -- even in the early days of 1994 or 1995 -- they were never something like that," Giustozzi says. "Even when they were fighting for power, they were not using these guerrilla tactics. They were more like an army moving along the highways and trying to occupy the provincial centers. In that sense, the main difference is the way they operate. It is not so easy to say what their actual aims are."
But he says that, too, might change.
"Essentially, they say what they want is just to get the foreigners out of the country," Giustozzi explains. "But even in the early days, they were claiming that their main aim was to pacify the country and bring back law and order -- not to become a kind of government which would stay in power indefinitely, which, of course, proved not to be correct once they actually took Kabul."
As for ordinary Taliban foot soldiers, recent research suggests that the Taliban has been recruiting a younger generation of Afghans to carry out suicide attacks and to fight within its rank and file.
Working for the United Nations Assistance Mission in Afghanistan, Christine Fair last year studied the phenomenon of suicide bombings across Afghanistan. Her work led to important conclusions not only about suicide bombers, but also about the emergence of this new generation of Taliban fighters.
"The important big picture is Afghans like to tell you that this is a Pakistani phenomenon," Fair says. "As we all know, there is Pakistani involvement. There is recruitment across the border. In the tribal areas, madrasahs figure prominently. But even if Pakistan went away, you still have a largely Afghan-driven insurgency."
Fair describes the situation as a "cross-border phenomenon," and says that "the insurgency is not going to be resolved if you think that the problem stops either at one side or the other of the Afghan border."
Her findings are supported by a series of interviews with Taliban fighters in Kandahar Province that was published online last month by Canada's "The Globe And Mail."
Those interviews suggest NATO air strikes and drug-eradication programs have fed the insurgency in southern Afghanistan. Many Taliban soldiers said their family members had been killed in air strikes or that they had been opium-poppy farmers until their crops were destroyed by drug-eradication teams.
Some said family members who were killed were innocent civilians. Others admitted that they joined the insurgency to replace older male relatives who were killed while fighting in the Taliban ranks. Complex Realities
Paul Fishstein, the director of the Afghan Research and Evaluation Unit, an independent Kabul-based research organization that receives funding from the United Nations, the European Commission, and other international donors, says that researchers should be careful not to oversimplify the demographics of today's Taliban.
"We always have to be careful about referring to 'The Taliban,'" Fishstein says. "Often, anything violent -- anything bad that happens -- is attributed to either 'the enemies of Afghanistan' or, more generally, 'The Taliban.'"
Fishstein concludes that the structure of today's Taliban is complex -- and that foreign researchers often have difficulty understanding the rivalries and local agendas that have contributed to the resurgence of the movement.
"What we generically refer to as 'The Taliban' is a set of different individuals and groups who have differing grievances, differing motivations, differing attitudes -- and take a hostile attitude toward the [Afghan central] government," Fishstein says. "There's an awful lot of groups out there that either have personal grudges, political grudges, or actually profit from the lack of law and order in the country."