Born in 540/1145, Najm al-din Kubra devoted himself entirely to the Sufi way of life. Kubra's main body of works concerns the analysis of the visionary experience. He wrote numerous important works discussing the visionary experience, including a Sufi commentary on the Qu'ran that he was unable to complete due to his death in 617/1220. Kubra died during the Mongol conquest and genocide after refusing to leave his city, where he fought in hand-to-hand combat against the Mongols