Thus started the manhunt for the leader of Al Qaeda( which translates to 'The Base' in English from Arabic). Bin Laden was of course hiding in Afghanistan under the protection of the Islamic fundamentalist group, Taliban, which was and is headed by the shadowy and enigmatic leader Mullah Omar. Taliban had been propped up by Pakistan to have control over Afghanistan and limit India's perceived hegemony in the region. Taliban is ultra conservative, with it's illiterate leader at the helm. It is mentioned about Mullah Omar in the book that the dude was so radical that he did not allow pictures of even himself, he refused to meet non Muslims and ordered the destruction of the Bamiyan Buddhas.
USA invaded Afghanistan to seek revenge, as Taliban had refused to handover Osama Bin Laden. America overthrew Taliban and launched scathing attacks on Al Qaeda. Many Al Qaeda leaders were either killed or captured but No 1 and No 2 remained elusive i.e. Bin Laden and his deputy Ayman Al Zawahiri.