Early August, Syria's rebels kidnapped 48 Iranian pilgrims in Damascus. The rebels claimed their prisoners were not pilgrims but in fact elite Iranian soldiers sent by Teheran to support the Assad government. A murderous sect known as the Assassins had a similar Iran-Syria partnership in the Middle Ages.

During the Middle Ages, the mountainous regions of Syria and Iran harbored the Ismailis, an esoteric Shi’a sect whose existence was marked by oppression and martyrdom. A radical branch known as the Assassins (Nizari Ismailis) were feared suicide attackers who terrorized the Muslim world from the 11th to the 13th centuries.

Although the Assassins are now considered predecessors of Islamic terrorists, the Christian Crusaders were lesser enemies to them than the Sunni principalities that they went after unrelentingly. Unlike “Twelvers” – the largest branch of Shi’a Muslims, who believe in 12 divinely ordained leaders, known as the Twelve Imams – the Ismailis, also known as the “Seveners,” believe that the true successor to the 6th Imam in 765 CE was not Musa al Kazim but his brother Ismail, and that the latter will return when the world ends.

When the Ismaili Fatimid Caliphate in Cairo – which lasted from 909 to 1171 – fell apart, the Ismailis were forced underground. And then in the Alborz Mountains of Iran a charismatic religious leader named Hassan-i Sabbah (around 1034-1124) spurred vengeance. From his fort of Alamut he developed a strategy of calculated terror that brought sudden death to sovereigns, princes, generals and governors, as British historian Bernard Lewis, author of a book on the Assassins, writes.

The bloody deeds of the individuals who carried out these killings were supposed to open a direct door to heaven for them, initiates and successful murderers who no longer had a future on Earth. Their fanatical leader was also a missionary and soon had a growing group of followers, primarily in Syria, where so many battles between Muslims and Christians played out.

Hassan-i Sabbah’s follower Rashid ad-Din Sinan (around 1133-1192), who was known as the Prince or Elder of the Mountain, began to terrorize Syria from his stronghold of Masyaf. While his name also became known in the West, most of his victims were among his Muslim neighbors.

It wasn’t until Masyaf Castle was surrendered to the Mongols in 1260 and then claimed by the Cairo Mamluks that the Assassins were wiped out.

Today, Aga Khan IV is the 49th Nizari Ismaili Imam, and the Ismailis are among the most tolerant and peaceful of Muslim sects. But in the ongoing Syrian uprising, the Damascus-Teheran axis of terror harks back to the medieval tradition of the Assassins.