Shah is a Persian term for a king (leader) that has been adopted in many other languages. Word history "Shāh" was the title of Iranian kings including the Achaemenid dynasty which unified Persia and created a vast intercontinental empire. The full title of the Achaemenid rulers was xšāyaθiya xšāyaθiyānām, "King of Kings", corresponding to Middle Persian šāhān šāh, literally "kings' king", and Modern Persian shāhanshā… (More on Shah)