In 1162, the sect's leader Ḥassan ʿAlā Dhikrihi's Salām sent him to Syria, where he proclaimed Qiyamah (repeating the ceremony of Hassan II at Alamut), which in Nizari terminology meant the time of the Qa'im and the removal of Islamic law.
Based at the Nizari strongholds al-Kahf and later Masyaf, he controlled the northern Syrian districts of Jabal as-Summaq, Maarrat Misrin and Sarmin.
He saw that the lamps in his tent were displaced and beside his bed laid hot scones of the shape peculiar to the Assassins with a note at the top pinned by a poisoned dagger.
Sinan's last notable act occurred in 1191, when he ordered the successful assassination of the newly elected King of Jerusalem Conrad of Montferrat.
[9] He was succeeded by the Persian da'i Abu Mansur ibn Muhammad or Nasr al-'Ajami appointed from Alamut, which regained a closer supervision over the Syrian branch of the Assassin Order.
[10] A fictionalized version of Rashid ad-Din Sinan (referred to as "Al Mualim", meaning The Mentor) appears as the main antagonist in Ubisoft's historical video game Assassin's Creed, voiced by Peter Renaday.