This article records tradition as it has been passed down and reported. Its sources are not yet part of the atlas's verified catalogue.
A century of intermittent warfare pitted the Nizari Ismaili state, founded when Hasan-i Sabbah seized the mountain fortress of Alamut in Persia in 1090, against the Sunni Seljuk Empire, which regarded the Nizaris as both a heretical and a politically subversive threat across Persia and the wider Islamic world. Rather than field armies to match the Seljuks, the Nizaris built a network of fortified mountain strongholds across Persia and later the Levant and answered Seljuk pressure with targeted assassinations of the empire's viziers, generals and provincial governors, most notably the vizier Nizam al-Mulk's 1092 killing, a tactic that gave the group its later Western name, the Assassins.
Neither side achieved a decisive victory. The Seljuks besieged Nizari strongholds repeatedly, most notably the siege that ended only with Sultan Muhammad Tapar's death in 1118, but never captured Alamut or the Nizaris' other major fortresses, while the Nizari state never expanded beyond its fortress network into a conventional territorial state. The conflict subsided as the Seljuk Empire itself fragmented into rival successor states after Sultan Sanjar's death, leaving the Nizari state to persist as an independent mountain enclave until the Mongol conquest of Alamut finally ended it in 1256, well beyond the span of this Seljuk-era war.