Shamsu-d-Dīn Muḥammad

Imam Shamsuddin Muhammad was sent to Azerbaijan before the attack of the Mongols, where he lived and became the next imam of Nizari Ismailis. He secretly lived there from the people of Azerbaijan and started working in a shop of embroidery. The Imam was so handsome that he was called Shams (Sun). He was a pious and kind person and lived a simple life. Only few people, who were closely related to the imam, could know about him. These were only his struggles that he spread the light spiritual education in Iran and Tabriz.

Juvaini writes in his "Tarikh-i Jhangusha"that, "Ruknu-d-Dīn now saw what he had to expect and realize that he could not resist. The next day, on November 16, 1256, he sent out his son, his only one, and another brother called Iran-Shah with a delegation of notables, officials and leaders of his people" (p. 717). This was the first narrative of Juvaini when Alamut was being reduced, but while describing the brutal massacre of the Ismailis after about a year, he writes, "And Qaraqai Bitikohi went to Qazwin with the order that Rukn-ad-Din's sons and daughters, brothers and sisters and all of his seed and family should be laid on the fire of annihilation" (p. 723).

In 13th century, after the Mongols conquered China and parts of Europe and Central Asia, they moved towards Iran and Bagdad. In 1257, Hulagu Khan easily destroyed the Ismaili Castles, and the Assassins surrendered their impregnable fortress of Alamut without a fight, accepting a deal that spared the lives of their people, and after an interval of a year, Hulegu attacked on the Abbasid Caliphate and destroyed the city and gradually went towards Aleppo in modern Syria. But when the Mongol forces tried to march towards Cairo, his forces faced a thorough defeat from the Mamluks who ruled Egypt at that time. Hulegu, himself, went to Tabriz and died in Maragheh on 1265. Muhammad Shah (d. 1404), son of Ala'udin Mumin Shah the eldest son of Imam Shamsuddin Muhammad, the grandson of the Imam was recognised as the rightful Imam by a group of Nizari Ismailis. They became known as the Muhammad-Shahi Nizari Ismailis. They followed this bloodline until their 40th Imam Amir Muhammad Baqir whom they lost contact in 1796. Imam Shamsuddin Muhammad appointed his younger son Qāsim Shāh as his successor whose descendants continue till present as Imams through the Aga Khan.