Esfandiyār (Persian: سپنديار), also translated as or Sepandiār, Sepandiyar, Esfandyar, Isfandiar, Isfandiyar or Esfandiar, is a legendary Iranian hero. He is also known as Belfian. He was the son and the crown prince of the Kayanian King Goshtasp (Middle Persian: Wishtasp, Avestan: Vishtaspa) and brother of the immortal Pashotan (Middle Persian: Peshotan, Avestan: Peshotanu).
Esfandiyār is best known from the tragic story of a battle with Rostam described in Ferdowsi's epic Shahnameh (Epic of Kings). It is one of the longest episodes in Shahnameh, and is one of its literary highlights.
The Perso word 'Sepandiār' is derived from Middle Persian 'Spandadat' or 'Spandyat' (the variance is due to ambiguities inherent in the Pahlavi script), which in turn derives from Avestan Spentodata meaning "Given by/through bounty" or "Given by (the) holy" (See Amesha Spenta for other meanings of spenta).
In the Shahnameh
According to the epic Shahnameh, Esfandiyār was the Crown Prince and a Divine Warrior of ancient Iran (or Persia) who supported the prophet Zartosht (Zarathustra), enabling him to spread the religion of Zoroastrianism. He also fought against many apostates and enemies of Zartosht to do so. In return, Zartosht gave Esfandiyār a chain and armor from Heaven. The armor made him invincible and the chain had the power to bind anyone, even a demon or evil magician, making them unable to escape. Zartosht also gave a Divine blessing to the prince and declared that anyone who spilled the blood of Esfandiyār (killed him) would suffer a cursed life and after death would be condemned to hell.
Esfandiyār's father, Goshtasp, had promised to give him the throne if he manages to repel an invasion in far-off provinces. Esfandiyār successfully carries out the order. Upon his return Esfandiyār's father informs him that during his absence the king of Turan Arjaasb had rebelled and attacked Iran's capital and abducted Esfandiyār's two sisters. Goshtasp sends Esfandiyār on another mission to suppress the rebellion and retrieve the abducted princesses.
Esfandiyār sets out in haste passing through a difficult and dangerous path with 7 different battles which would be known later as 7 labors of Esfandiyār. Esfandiyār then successfully infiltrates the Fortress of Arjaasb known as Roin Dej. (lit. Invincible Fortress) Esfandiyār then kills Arjaasb, rescues his sisters and conquers the fortress. Upon Esfandiyār's return to Iran Goshtasp, who did not want to part with his throne, hedges once again.
Although Goshtasp is aware of a prediction that foretells the death of Esfandiyār at the hand of Rostam – compels the young hero to go and bring the aging Rostam in chains for his arrogance and disrespect toward the king, promising that upon completing this mission he will certainly this time gives the throne to Esfandiyār and retire himself. Although Esfandiyār initially protests, reminding his father of Rostam's fame, great age, and services to the dynasty, he eventually complies with his father's wishes and sets out towards Rostam's home.
Upon reaching the home of Rostam, Esfandiyār delivers the message, but Rostam refuses to comply to be put in chains, accepting only that he will accompany the young prince to his father's palace. Esfandiyār tries to insist. Rostam, making numerous other concessions, stands his ground and the two eventually meet in single combat. In the subsequent battle, the invincible Esfandiyār is unaffected by Rostam's blows while Rostam is seriously wounded by Esfandiyār's arrows which had diamond arrowheads and could easily pierce through Rostam's armor. Pleading respite to dress his wounds, Rostam withdraws.
Rostam learns from Simurgh of the only weapon that can affect Esfandiyār: a shot to the eyes from a special double-headed arrow made from the branch of a tamarisk tree near the sea of China. The Simurgh warns Rostam about the fate that awaits the killer of Esfandiyār and asks Rostam to consider surrendering to the Prince. Rostam refuses to accept the shame of surrendering and being chained by anyone. Upon making this decision Simurgh carries Rostam to a tamarisk tree. Rostam fashions the double head arrow with a feather of Simurgh and a twig of the tamarisk tree. When the battle resumes the next morning, Esfandiyār is blinded by a shot through the eye.
In the end before dying, Esfandiyār tells Rostam not to blame himself. It was the false promise of his father Goshtasp and the Arrow of Simurgh that killed him. Esfandiyār then tells Rostam that he is not guilty in this, but the real murderer who should be cursed is Goshtasp.