Rashid ad-Din Sinan

Rashīd ad-Dīn Sinān (Arabic: رشيد الدين سنان‎), also known as the Old Man of the Mountain (Arabic: شيخ الجبل‎ Shaykh al-Jabal, Latin: Vetulus de Montanis)[1][2] and also referred to Rashid al-Din Sinan (1132/1135–1193), was a missionary[3] and a leader of the Syrian branch of the Nizari Ismaili state (the Assassins), and a figure in the history of the Crusades.