What different forms does terrorism take and what do they have in common? Explosives carried in the rucksack. A bomb under a park bench. A hi-jacked aeroplane. Today these images of terrorism are broadcast into our homes. Terrorism itself embodies far more than this, however. Those who create terror are not just organizations such as al Qaieda and ETA but also states and repressive governing regimes. Spanning 2000 years and 3 different continents, Rosemary H.T. O'Kane explores terrorism in all its forms: terrorist groups, ancient and modern, religious, political, separatist and nationalist, arising within liberal democracies and under repressive regimes, engaging in domestic, international and transnational terrorism; revolutionary reigns of terror; totalitarian regimes; state terrorism, including massacres and genocidal campaigns; and international state terrorism. Case studies are included and explanations are explored for each of these many terrorisms. No matter the form, however, the method remains essentially the same - a system of summary justice: in its essence the deliberate targeting of innocents as victims.