The year is 320. Under the rule of the belligerent King Andragoras III, the Kingdom of Pars is at war with the neighboring empire, Lusitania. Though different from his father in many aspects, Arslan, the young prince, sets out to prove his valor on the battlefield for the very first time. However, when the king is betrayed by one of his most trusted officials, the Parsian army is decimated and the capital city of Ecbatana is sieged. With the army in shambles and the Lusitanians out for his head, Arslan is forced to go on the run. With a respected general by his side, Daryun, Arslan soon sets off on a journey in search of allies that will help him take back his home.