Excerpt: Yazdegerd I (399–420) was the monarch represented with a crescent moon on the front of his crown.
Farrukhzad, the previously minister of Yazdegerd, and ruler of Tabaristan, managed to repel the Arabs with the aid of Gil Gavbara and make a treaty with them.
After the Sasanian disaster, Yazdegerd fled to Isfahan and then Estakhr where he tried to organize a base for resistance in the province of Pars.