Muhammad Tapar's anti-Nizari campaign

Sultan Muhammad Tapar of Seljuq Empire began a campaign against the Nizari Ismaili state (a series of strongholds inside the Seljuq territory) soon after gaining power and putting an end to internal strifes of the empire. Being heavily outnumbered, the Nizari Ismailis initially suffered setbacks, losing their influence in the Zagros Mountains, Isfahan, Iraq, and northern Syria. However, resistance in the main Nizari strongholds of Alamut and Lambasar was fierce, and despite being continually reinforced and waging a prolonged war of attrition for years, the Seljuqs failed to capture these castles. After Muhammad Tapar's death in 1118, the Seljuq forces under Anushtegin Shirgir immediately left Rudbar, and the campaign ended as a stalemate, with the Seljuqs failing to reduce the Nizari strongholds and the Nizari Ismaili anti-Seljuq revolt losing its initial effectiveness.