“Muhammad bin Kiya Buzrug was born in 490/1097 probably in the fortress of Lamasar. He was given training by his father, and proved an able and competent administrator. He was assisted by his one young brother Kiya Ali, who led many expeditions and died in 538/1144. In the early part of Muhammad bin Kiya’s reign, the area in control of Alamut was extended in Daylam and Gilan, where several new castles were taken or constructed, such as Sa’adatkuh, Mubarakkuh and Firuzkuh. These castles were acquired chiefly through the efforts of an Ismaili commander, called Kiya Muhammad bin Ali Khusaro Firuz. The Ismailis are also reported to have extended their mission to Georgia, and penetrated their influence in an entirely new region, Ghor, to the east of Kohistan, between Ghazna and Herat in central Afghanistan, around 550/1155 during the period of the Ghorid ruler Alauddin (544-556/1149-1161). His son and successor Saifuddin Muhammad (d. 558/1163) was a deadly enemy of the Ismailis, and conducted a massacre of the Ismaili da’is and the new converts in 557/1162 at Ghor. Henceforward, it became a tradition of the Ghorids to hunt and kill the Ismailis in Afghanistan and India. Ghiasuddin (d. 599/1203), the nephew of Alauddin ascended the throne, who appointed his brother, Muhammad to the government of Ghazna with a title of Shihabuddin. After the death of Ghiasuddin, his brother Shihabuddin Muhammad rose to the power, assuming the title of Muizzuddin instead of Shihabuddin, who made several military operations in India.
Meanwhile, the northern Iranian Ismailis were confronted with Shah Ghazi Rustam bin Ala ad-Dawla Ali (534-558/1140-1163), the Bawandid ruler of Mazandaran and Gilan. It is recounted that Shah Girdbazu, the son of Shah Ghazi, was sent to Khorasan to serve at the court of Sanjar, but he had been killed by the Ismailis in 537/1142, and in another attempt, Shah Ghazi himself was rescued. The sources at our disposal admit that the Bawandid ruler Shah Ghazi shook his hand with the Seljuqs and fought the Ismailis on numerous occasions, and also invaded Alamut, which remained foiled all the times. He however seized the castles of Mihrin and Mansurakuh from the Ismailis in Qummis. On one occasion, Shah Ghazi attacked on the Ismaili inhabitants of Rudhbar and devastated their properties. He had reportedly killed a large number of the Ismailis and erected towers of their heads.
In 535/1141, the Ismailis are said to have killed their deadly enemy Jawhar, the Seljuqid commander in Sanjar’s camp in Khorasan. Abbas, the Seljuq amir of Ray, had slaughtered a large number of the Ismailis in reprisal. He also raided the Ismaili localities near Alamut. His terrible operations remained continued, therefore, the Ismailis sent an emissary to sultan Sanjar in 541/1146, asking his intervention in this context. It appears that Abbas did not refrain from his hostilities despite several attempts of Sanjar. He was however killed on his way to Baghdad, and the Seljuqs sent his head to Alamut.
The Seljuqid sultan Sanjar once arrived in Ray, where he had been misinformed the doctrines of the Ismailis. He sent his messenger to Alamut to know the creeds of the Ismailis. The Ismailis gave a reply to the messenger that, “It is our principle to believe in the grandeur and greatness of God, to obey His ordinances, to act on the Shariah as shown by God in Koran and by His Prophet, and to have a faith in dooms-day, reward and punishments of deeds. No one is authorized to alter these ordinances at his will.” The messenger was further told, “Tell to your king that these are our beliefs. It is well if he is satisfied, otherwise send his scholar, so that we may discuss with him.” It appears that Sultan Sanjar refrained from his inimical attitude towards the Ismailis after getting above reply. Juvaini (p. 682) writes that, “I saw several of Sanjar’s farmans which had been preserved in their (Ismailis) library (of Alamut) and in which he conciliated and flattered them; and from these, I was able to deduce the extent to which the sultan connived at their actions and sought to be on peaceful terms with them. In short, during his reign they (the Ismailis) enjoyed ease and tranquility.”
The promising time for Ismaili Imam’s appearance from dawr-i satr (concealment period) was very near, therefore, Imam al-Kahir bin al-Mohtadi bin al-Hadi bin al-Nizar took over the power of Nizari state from Muhammad bin Kiya Buzrug in 554/1159 and designated him as his vizir.
Muhammad bin Kiya Buzrug died on 3rd Rabi I, 557/February 20, 1162 and was buried next to the tombs of Hasan bin Sabbah and Kiya Buzrug Ummid. He governed as a ruler for 22 years, and 2 years as a vizir of Imam al-Kahir.