The suicide attacks of 11 September 2001 originated deep within Islamist circles. One of the prime suspects behind the attack, the Egyptian Ayman al-Zawahiri, was heavily influenced by Egypt's radical movements and by Sayyid Qutb, a Muslim Brother who became a prime advocate of jihad and renewed Islamist thought in the 1950s. Widely considered the heir to this legacy, al-Zawahiri remains a driving force behind al-Qaeda itself. Gilles Kepel, one of the world's leading experts on Islamist movements, was amongst the first to identify Egypt as the cradle of contemporary Islamism. This seminal work, with a new introduction that puts it in perspective, gives a profoundly perceptive account of the foundations of today's radical Islamic organisations, and offers compelling insights into the structure, theory and tactics employed by the various groups as early as the 1970s in Egypt.