During the late 11th century, an order of Nizari Ismailies was formed in Persia and Syria by a man called Hassan-i Sabbah. These were the notorious Hashshashins who captured many mountain fortresses and posed a threat to Sunni Seljuk authority in Persia. Perhaps the Hashshashin were most famous for the way they got rid of their opponents – through highly-skilled assassinations. In fact, the word ‘assassin’ is said to have originated from this order.