An gwabza yakin Nahavand a shekara ta 642 tsakanin dakarun musulmi Rashidun karkashin halifa Umar da sojojin Farisa Sasania karkashin sarki Yazdegerd na uku.Yazdegerd ya tsere zuwa yankin Merv, amma bai iya tara wata babbar runduna ba.Nasara ce ga Khalifancin Rashidun kuma Farisawa suka yi hasarar garuruwan da ke kewaye da su ciki har da Spahan (Isfahan).Tsoffin lardunan Sassanid, tare da kawance da masu fada a ji na Parthian da White Hun, sun yi tsayin daka na kusan karni guda a yankin kudu da Tekun Caspian, kamar yadda Umayyawa suka maye gurbin Halifancin Rashidun, don haka ya ci gaba da dawwamar salon kotunan Sassanid, addinin Zoroastrian, da kuma Harshen Farisa.