This chapter introduces the reader to the ideology of the man who is considered to have laid the foundations for the establishment of al-Qaida, the spiritual guide of Usama Bin Ladin and many other radical Muslim ideologists of our generation. It deals with the major principles of Abdullah 'Azzam's belief, his concept of the Muslim state, and his link to the extreme Egyptian ideologist Sayyid Qutb, with the theory of Global Islamic Jihad he formed in Afghanistan and with his relation to the Jews and the State of Israel. The chapter argues that the first stirrings of Global Islamic Jihad already appeared with the territorial spread of Islam out of the Arabian Peninsula. The theory of the Global Islamic Jihad was perceived by 'Azzam as a battle between religions. This theory is implemented in two parallel levels: the militant Jihad (the holy war) and the Da'wah (the Islamic propaganda).