Kammala wannan jumla: A kusan shekara ta 650 CE, a lokacin da Larabawa suka ci daular Sassanid, Sarkin daular Sassanid Yazdegerd III yana kokarin sake tattarawa da tara sojoji a kusa da Tokharistan kuma yana fatan samun taimakon Turkawa, bayan da ya sha kaye a hannun Larabawa a cikin
Yaƙin Nihâvand (642 AZ). Yazdegerd da farko ya sami goyon bayan Hephthalite Principality na Chaghaniyan, wanda ya aiko masa da sojoji don taimaka masa a kan Larabawa. Amma lokacin da Yazdegerd ya isa Merv (a cikin abin da yake a yau Turkmenistan) ya bukaci haraji daga "Marzban" na Marw, ya rasa goyon bayansa kuma ya sanya shi abokantaka da sarkin Hephthalite na Badghis, Nezak Tarkan. Sarkin Hepthalite na Badghis ya haɗu da "Marzban" na Merv ya kai hari ga Yazdegerd kuma ya ci shi a 651. Yazdegerd III da kyar ya tsere da ransa amma an kashe shi a kusa da Merv ba da daɗewa ba, kuma Larabawa sun yi nasarar kama garin Merv a wannan shekarar.