The Order of Assassins (Arabic: حَشّاشِین, romanized: Ḥashshāshīyīn; Persian: حشاشين, romanized: Ḥaššāšīn) were a Nizari Isma'ili order that existed between 1090 and 1275 AD, founded by Hasan al-Sabbah. During that time, they lived in the mountains of Persia and the Levant, and held a strict subterfuge policy throughout the Middle East, posing a substantial strategic threat to Fatimid, Abbasid, and Seljuk authority, and killing several Christian leaders. Over the course of nearly 200 years, they killed hundreds who were considered enemies of the Nizari Isma'ili state. The modern term assassination is believed to stem from the tactics used by the Assassins. Contemporaneous historians include ibn al-Qalanisi, Ali ibn al-Athir, and Ata-Malik Juvayni. The former two referred to the Assassins as batiniyya, an epithet widely accepted by Isma'ilis themselves. Source: Wikipedia (en)