According to most sources, Gundishapur was the last major city in Khuzestan that the Arabs conquered. According to al-Tabari and al-Baladhuri, Abu Musa Ashaari marched to Gundishapur and besieged the city in 642.[11] The city didn't put much of a resistance, due its weak defence mechanism; only after a few days, the city surrendered and opened its gate.