On a hot summer's day in 1996 a plane carrying Osama bin Laden and a few friends and family landed at a runway just outside the eastern Afghan city of Jalalabad. The Saudi-born Islamic activist had little equipment, few followers and minimal local support. Yet within five years he had built an organisation that was to carry out the most shocking and devastating terrorist attack in history. 'Al-Qaeda' is now the most over-used and misunderstood term...