Naser al-Din Shah Qajar was the fourth Shah of Qajar Iran from 5 September 1848 to 1 May 1896 when he was assassinated. He was the son of Mohammad Shah Qajar and Malek Jahan Khanom and the third longest reigning monarch in Iranian history after Shapur II of the Sassanid dynasty and Tahmasp I of the Safavid dynasty.