TLDR Imamat History: Persia
With the help of Dai Abdul Hasan Saidi, alHadi escaped prison in Cairo and fled to Persia. Dai Hassan bin Sabbah called the leaders of various Nizari fortresses to meet the new Imam on his arrival to Alamut. Under the protection of these leaders, and the newly formed Fidais, alHadi lived a protected life in the fortress of Lamasser, even though his cousin, the Caliph of the Fatimids sent out campaigns to defame him.
Muhtadi became the Imam at the age of 45 and also lived a protected life in Lamasser, under the watch of the Dais and Fidais. The Dais handled many of the affairs of state, including a increasing frequency of political assassinations.
Qahir only reigned as Imam for about five years, still under the protection of the Fidais, who were now an infamous political force in the area. During this time, Fidais conquered a couple more fortresses to keep morale high and sucessfully assassinated the Abbasid Caliph Rashid.
Imam Ala Dhikrihi asSalam
Ala Dhikhrihi asSalam became the Imam at the age of 32. Before him, the Ismaili Mission and government issues were handled by the Dais, who were spread through various fortresses in Persia and Syria, but Ala Dhikrihi asSalam took these matters into his own hands. While the previous four Imams had lived in hiding, and Ismailism and its practices were strictly secret, Ala Dhikrihi asSalam declared his Imamat publicly in an event known as Qiyama (resurrection). Now Nizaris could live openly amongst their Sunni neighbors and practice their faith esoterically (as opposed to strict exotericism). Ala Dhikrihi asSalam's brother-in-law Husayni Namawar opposed these new policies and poisoned Ala Dhikrihi asSalam after just 5 years of reign. Before his death, Ala Dhikrihi asSalam was a friend and teacher to Rashid adDin Sinan, who later went on to implement the Imam's plurastic reformation across Nizari territory.
Imam Ala Muhammad
Ala Muhammad became the Imam at the age of 19 and further encouraged his father's policies. Even though the community now encouraged pluralism and peace, the Fidais remained on guard for the community's defense. At this time, the Fatimid Dynasty was overthrown by Saladin who was taking over the Seljuk Empire, and the Abbasid Caliphate was quickly dissolving. It was also during this time that Rashid adDin Sinan travelled between Nizari fortresses, conducting repairs and construction, building relationships with local governments, and clashing with Crusader and Sunni forces along the way.
Imam Jalaluddin Hassan
Imam Ala Dhikrihi asSalam's (and Imam Ala Muhammad's) Qiyama policies continued to draw opposition within the Nizari community, so Jalaluddin Hassan reinstituted Sharia and exotericism for Ismailis. In a further effort to restore relationships with neighboring Sunnis, Jalaluddin Hassan publicly sent his mother on pilgrimage with the Abbasid delegation; she provided charity and dug wells along the way (to emphasize the values behind the Ismaili Mission). This political stunt gained Jalaluddin Hassan the approval of governments in Mecca, Baghdad, Aleppo, and Cairo. These alliances, along with the return to Sharia, allowed Muslims of the Middle East to build a united front against the Crusaders. Jalaluddin Hassan (and later, his son) also married into Khwarizmi royalty in order to secure an alliance with Persia. After ten years of making political connections as Imam, Jalaluddin Hassan died of dysentary.
Imam Ala adDin Muhammad
Ala adDin Muhammad became the Imam at the age of ten. He continued his father's Sharia policy for another ten years, but reconsidered as he saw the political situation change. Ala adDin Muhammad spent his Imamat securing a future for his community. He reached out for allegiences with the Mongols, sending ambassador Badr adDin Ahmed. But the Mongols were the Mongols and didn't agree to anything. He then approached the Crusaders to create an alliance against the Mongols, not knowing that the Crusaders were already trying to ally with the Mongols. At the same time, Pir Satgur Noor travelled to Gujarat to secure relationships with Tayyabi Ismailis (who had previously followed Mustaali in Cairo) as well as convert Hindu communities to Nizari Ismailism. Eventually, Ala adDin Muhammad was killed by his friend and advisor, scholar Hasan Mazandarani, for reasons unknown.
Imam Rukn adDin Khair Shah
While the Mongols continued to take over the world, General Hulagu Khan was assigned by his brother to take over the Middle East. Khan had an easy march toward Iran, with local lords quickly surrendering to the ruthless Mongol army. Rukn adDin Khair Shah, knowing the Fidais couldn't defeat the Mongols, wrote to the Khan in hopes of an honorable surrender. Hulagu Khan ordered the destruction of Nizari fortresses and the personal surrender of the Imam. Rukn adDin Khair Shah sent a number of emmisaries and safely deconstructed a few of his minor forts to appease the general but Khan continued his march to Rudbar, where Rukn adDin Khair Shah lived and desperately stalled for time, murdering Nizari leaders and destroying fortresses along the way. Finally, Hulagu Khan reached the foot of the Imam's fortress and demanded his surrender. Rukn adDin Khair Shah hesitated, but surrendered at the advice of his council. With the Imam as leverage, the general ordered the surrender of all the Nizari fortresses. About 100 forts were surrendered, evactuated, and then destroyed. In gratitude for the surrender of Nizari fortresses, the general presented the Imam with 100 camels and a wife before turning his sights to Lamasser and Alamut, two of the strongest forts that hadn't yet surrendered. Rukn adDin Khair Shah was escorted back to the court of Mangu Khan, but was murdered along the way. The Mongols orchestrated the murder of all of the Imam's family members who had since scattered throughout Persia and Syria.