1.Cyrus -the great 2.Ashoka 3. Shahjahan 4.Alexandar
According to my point of view Alexander is the King of the World.People calling him by name of Alexander the great and Sikander(in India).He had the dream of conquer the whole world under his name.He was basically from macedonia which comes under the Greece.He started his journey of victory from Greece then conquered the Egypt and Persia,then he moved towards Asia.when he reached to Beas river then he fought with Porus(king of punjab region). He defeated the porus and planning to cross the river beas,but Chanakya and chandragupta maurya stopped him.That time alexander got sick and due to this incident he returned to Babylon.He died at the age of 33.But he had real skills of leadership which motivates their Army.
Ashoka is a great emperor who , expanded the mouryan dynasty still Afghanistan from west to Bangladesh of present day to the east.he followed the preaching of gutham bhudha.also showed his mark of governance and implemented special schemes to people of mourya.