Terrorism, whether practiced by states, substate groups, or individuals, is found throughout human history. Most historical accounts, however, focus on what they take to be forms of terrorism that are practiced by substate groups and individuals.

During Biblical times, Jewish Sicarii, known for their use of a short sword (sica), struck down rich Jewish collaborators who were opposed to violent resistance against their Roman conquerors. Later, in the eleventh and twelfth centuries, a group of Shiite Moslems, called the Assassins, opposed efforts to suppress their religious beliefs in Sunni-dominated Persia. Using daggers, the Assassins killed prefects, governors, and caliphs in front of many witnesses, thus ensuring their capture and execution because they believed that by their actions they would gain entry into paradise. Eventually, the group was suppressed by the Mongols in the thirteenth century.

In India, from the eleventh century on, a group called the Thugs was...