It is the year 320. The Kingdom of Pars is at war with the neighboring realm of Lusitania, led by the belligerent King Andragoras III. Arslan, the young prince, sets out to prove his valor on the battlefield for the first time, despite being extremely different from his father in many ways. The Parsian army is destroyed and the capital city of Ecbatana is besieged when the monarch is betrayed by one of his most loyal officers. Arslan is forced to flee with his army in shambles and the Lusitanians want his head. Arslan sets out on a voyage in quest of allies to help him reclaim his homeland, accompanied by a distinguished commander named Daryun.