The child, named Arslan for the proud and mighty Lion, grew up as hardly anything close to a noble, but he showed himself to be incredibly gifted in mental and physical disciplines, able to learn Arabic and Persian and seven other languages, while also mastering the arts of combat. Even as a child he managed to impress the khedive of Egypt.
Then, Arslan's true bloodline is revealed – an envoy arrives on the orders of King Patras, conqueror of Rum, and the envoy sent the king's demands the royal child, his mother and No'man are brought to his court at once, lest King Patras destroy Cairo as well. Arslan was shocked at the revelation of his identity as a prince, and while he felt anger towards his adoptive father, his anger at King Patras for killing his true father and taking over his rightful home was far greater. He had the envoy killed, and the Patrasian men who arrived by ship were all killed by outraged Egyptians who have come to respect young Arslan.
Arsland respected his people and loved the country that had made him a man, and so he exiled himself and set out to conquer the Patrasians and retake his homeland of Rum. With great skill he did so, and the Europeans were ousted from the throne.
His adventure takes a new turn, though, when he sees the portrait of a beautiful woman – the daughter of King Patras himself, Farokh Lagha. Arslan was immediately besotted with this girl, and sought her out, going alone to the capital of Patrasia, deep in Europe, despite being forewarned by astrologers that his journey would not end well. He made it to the city, and tried to sneak in the front gate – there he met Tavus, gate guard and secretly a Muslim. As a good Muslim, Tavus let his brother of the faith into the city, and got help from his actual brother, Kavus. The two both learned his true identity upon seeing the prince, so he was hardly a secret, but they passed him off as Elias, a worker in a coffeehouse. However, this disguise didn't work so well; the king's viziers, Shams and Qamar, the ministers of the sun and moon respectively, both suspected his identity and sought him out.
They both came to him separately and in secret, urging him to reveal his secret, and each of the viziers worked against the other, with Shams telling Arslan that Qamar is not to be trusted, and vice versa. Arslan didn't take this so well, and decided to stay secret as Elias, until the situation changed drastically.
The princess, Farokh Lagha, was betrothed to the son of the European king Papas, named Hushang, and their wedding was set for very soon. Arslan had to act, and he caught the attention of the princess herself; he learned that she loved him just the same, and together they worked to thwart the wedding. As clever as he could be, Arslan failed to stop the wedding from occurring, but he nonetheless managed to make it a complete disaster, and Hushang ended up dying shortly thereafter.
Arslan's identity was no secret by that point, and as a foreign prince he was held in suspicion for the recent events, and Farokh Lagha appeared to be murdered in reciprocation for the death of Hushang. At this point, vizier Qamar stepped in to help Arslan, getting him out of the city and out of danger... but this ended up backfiring, with Arslan transported to a magical, foreign land full of great deserts and ancient landscapes by the vizier's wild magic. It ended up that both he and the princess were brought to this place, far from home, and Arslan has to face many trials to reunite with her.
Farokh Lagha, trapped by the evil king Malek Khazen, was powerless to escape and so Arslan had to win her back. However, Malek Khazen was in control of a great country and a huge army, and all seemed hopeless for Arslan – especially since the head general of the king was a demon that no man could even harm. Through his cleverness and skill, Arslan managed to form a fighting force and conquer himself his own kingdom in the magical world, all while suffering through many fantastical ordeals, worthy of the great heroes of old that Arslan only read about.
He made his breakthrough when he finally stole the sword Shamshir-e Zomorrodnegar from the demon general, and slew the beast with it, leaving the king's army with no head. Victory came soon afterwards, and with Arslan reunited with Farokh Lagha at last, he managed to escape back to his own world with the magic of the fantasy realm.
Back in nineteenth century Europe, Arslan found king Patras warring against king Papas over the murder of Farokh Lagha and prince Hushang; Patras forgives Arslan for all that had happened when his daughter is returned to him, and permits the two to marry.
There, the story ends, but naturally Arslan must have had many great adventures afterwards as well, of course.