Al-Qaida's history isn't ancient; it was started in 1988, at the tail end of the Soviet-Afghan war. Native Saudi Osama bin Laden had been a strong supporter of the anti-Soviet Afghan fighters, and after the conflict he was eager to create an affiliated network of Islamic extremists that had come together during the war [source: MI5].
This international mission was unusual. In general, most Islamic extremists groups were tied to local causes. From 1990 to 1996, al-Qaida's influence wasn't terribly strong; Saudi Arabia had revoked bin Laden's citizenship, and al-Qaida's base shifted to Sudan. But bin Laden continued to see the West (more specifically, the United States) as the corrupting force in the Muslim world. After moving to Afghanistan, al-Qaida issued a "declaration of war" against the U.S. in 1996.
It was in Afghanistan where al-Qaida began to build a serious infrastructure, and terrorist attacks followed. Al-Qaida ambushes on embassies in Kenya and Tanzania, as well as the USS Cole in Yemen, killed hundreds of people [source: MI5]. These bombings also established a modus operandi for al-Qaida operatives: mass casualty through suicide missions.
It's during the period from 1996 to 2001 that al-Qaida also formed a key relationship with the Taliban in Afghanistan. Initially, the Saudi-based al-Qaida fighters (of which there were only about 30 who first came to Afghanistan) and the Afghani Taliban were leery of each other -- again, the Taliban were one of the organizations that had little interest in the "far enemy" of the West [source: Dreyfuss]. But as al-Qaida gained power and structure, the Taliban agreed to harbor bin Laden and the organization in Afghanistan [source: Dreyfuss].
While 9/11 was certainly the piece de resistance of al-Qaida, the events of September 2011 also threw the organization into a mad scramble. The U.S.-sponsored invasion of Afghanistan led to an overthrow of the Taliban, and the al-Qaida infrastructure was in shambles as its members were forced to flee into the Pakistani/Afghani border (and wilderness). Along with a breakdown of communication, money was suddenly very difficult to get a hold of as the international community cracked down on financing trails.
Which brings us to Osama bin Laden's death and al-Qaida 3.0.