Sayyid Qutb
Sayyid Qutb could be said to have founded the actual movement of radical Islam. Unlike the other writers that have been mentioned above, Qutb is not an apologist. Some of the proponents of Islam emphasise peaceful political processes, whereas Sayyid Qutb in particular called for violence, and those followers are generally considered Islamic extremists and their stated goal is Islamic revolution with the intent to force implementation of Sharia law and/or an Islamic State Caliphate.