Yazdegerd III

Yazdegerd III was the last Shah of Persia before the Islamic conquest of the Persian empire. With his empire weakened by war with the East-Roman empire, internal conflicts and the plague, he was unable to defend the strong Persian legacy against the military might of the Arabs. This is despite a vast cultural, philosophical and technological superiority.

Sources:
https://www.britannica.com/place/Persia
https://about-history.com/arab-conquest-of-persia-sassanian-empire/
Letter from Yazdegerd III - https://www.persepolis.nu/timeline-letters.htm
https://dragonsarmory.blogspot.com/2018/05/a-prince-of-persia-last-sassanids-in.html
https://www.geni.com/people/Yazdgerd-III-Shah-of-Persia/6000000007715599496
https://www.britannica.com/place/Ctesiphon-ancient-city-Iraq