Among the cities listed, Jerusalem was part of the Byzantine Empire the longest. After the Eastern Roman Empire (Byzantine Empire) was established following the division of the Roman Empire, Jerusalem remained under Byzantine control until the Persian conquest in 614 AD and was subsequently retaken by the Byzantines in 629 AD, continuing as part of the empire until the Muslim conquest in 636 AD.
Athens, as part of the Byzantine Empire, also had a significant period, but Jerusalem is notable for its longer duration of Byzantine influence, especially given its religious significance. Kiev was not a part of the Byzantine Empire for as long as Jerusalem, as it was more directly aligned with the Kievan Rus.
Overall, given the specific historical contexts, Jerusalem is the answer to the question.