The history of terrorism stretches back nearly two thousand years and terrorism, both in the forms of terrorist groups and terror regimes, is an inherent part of the modern world: from Anarchist groups to al-Qaida; from Hitler\'s Germany and SS to al-Bashir\'s Sudan and Janjaweed militias. It is a subject of high current interest that is rarely out of the news (not least as the legacy of \'9/11\') and it is also of enduring interest. As a new volume in the Seminar Studies series, Terrorism has been brought up-to-date and now looks at both contemporary terrorism and its historical antecedents, providing a much needed introduction to the subject.