“The word kiya means lord or ruler. Buzrug Ummid or Kiya Buzrug Ummid was the second hujjat and ruler after Hasan bin Sabbah in Alamut, who most probably was born in 455/1062 in the peasant family of Rudhbar. He passed most of his childhood in Rudhbar in cultivation of his father’s land. Kiya Buzrug Ummid had been a handsome young page, whom Hasan bin Sabbah had converted before almost 480/1087. He played a leading role during the possession of Alamut in 483/1090. He was an outstanding organizer, talented da’i and an able administrator. Hasan bin Sabbah had sent him with a troop to conquer the fortress of Lamasar in 489/1095. He defeated a certain Rasmasuj and took possession of Lamasar, known as Rudhbar-i Alamut.
Kiya Buzrug was confronted with the animosity of the local amirs as soon as he assumed the power. In 518/1124, some 700 innocent Ismailis had been butchered mercilessly near the Postern gate (bab as-sirr) at Amid (the Roman Amida) in Diyar Bakr.
It appears that the Seljuq sultan Sanjar had refrained from launching further operations, possibly due to his pact with Alamut. When Alamut came to be governed by Kiya Buzrug, sultan Sanjar took militant stance to test the capability of the new leadership of the Ismailis. In 520/1126, he sent a large army at the command of his vizir against Turaythith in Kohistan, as well as Bayhaq and Tarz in the district of Nishapur, with orders to massacre the local Ismailis and sack their properties. This expedition sent from Khorasan was fissiled of no result. The expedition sent in the same year by sultan Muhammad to Rudhbar at the command of Asil, the Ismaili warriors repulsed the nephew of Anushtagin Shirgar. The Ismailis of Rudhbar, who captured one of the enemy’s amirs, Tamurtughan, also foiled another Seljuq attack in the same year. He was taken prisoner to Alamut for some months. Tamurtughan was however released upon the request of sultan Sanjar.
During the rule of Kiya Buzrug, several other fortresses were seized, including Mansura and others in Taliqan, while a few castles were built, such as Sa’adatkuh in 521/1127.
In 523/1129, the sultan Muhammad entered into peace negotiations with the Ismailis, and for this purpose, he invited Alamut to send an envoy to Ispahan. Kiya Buzrug dispatched Khoja Muhammad Nassihi Shahrastani. But the discussions proved abortive as the Ismaili emissary and his colleagues had been killed by some of the town people while they were leaving the Seljuq court. The sultan disclaimed the responsibility, also rejecting to punish the assassins. Thus, the Ismaili forces, in reprisal attacked Qazwin, killing 400 persons and taking away much booty.
Sultan Muhammad executed another unsuccessful raid at Alamut district, while an army was also sent from Iraq in 525/1131 against Lamasar with 30,000 soldiers, but of no avail. Meanwhile, Sultan Muhammad died and his army retreated, and after that the fortress of Lamasar was never invaded.
By the end of Kiya Buzrug’s reign, the Ismailis had clearly established an independent state of their own. This state primarily consisted of two areas in Iran, namely Rudhbar and a large tract of Kohistan, as well as the southern part of the Jabal Bahra in Syria. At the same time, there were non-Ismailis, including Sunnis, Ithna Asharis, Zaidis and Nusairis living in the areas dominated by the Ismailis. The Nizari state had its own mint as an accepted territorial rule. Kiya Buzrug’s adoption of the role of a territorial ruler and his acceptance by others as such, are strikingly demonstrated by the flight to Alamut in 530/1136 with his followers of a certain Seljuq amir Yaranqush, an old enemy of the Ismailis. He was dislodged from his iqta (an administrative grant of land) by Khwarazmshah and took refuge at Alamut. According to Jamiut Tawarikh (p. 142), the Shah asked for his surrender, arguing that he had been a friend of the Ismailis, while Yaranqush had been their enemy. Kiya Buzrug refused to deliver him to Khwarazmshah, saying: “I cannot reckon as an enemy anyone who places himself under my protection.” This reflects indeed a chivalrous and greatness of Kiya Buzrug.
Kiya Buzrug Ummid excelled in his works that Hasan bin Sabbah had reposed in him. He died on 26th Jumada I, 532/February 9, 1138 after ruling for 14 years, and was buried next to the tomb of Hasan bin Sabbah. He was succeeded as the third ruler by his son Muhammad bin Kiya, whom he designated only three days before his death according to the order of the Imam. According to Rawzatus-Safa (4:78) that, “The enemies of Kiya Buzrug became joyful and insolent, but they were made soon to realize that their hopes were vain.”