In the summers of 851 to 854, Ali ibn Yahya al-Armani, emir of Tarsus, raided imperial territory, perhaps viewing the empire being governed by a young widow and her child as a sign of weakness. Though Ali's raids did little damage, Theodora decided to retaliate and sent raiding parties to raid the coastline of Egypt in 853 and 854. In 853, the Byzantine raiders burnt down the Egyptian city of Damietta and in 855, a Byzantine army invaded Ali's emirate and sacked the city of Anazarbus, taking 20,000 prisoners. On Theoktistos's orders, some of the prisoners who refused to convert to Christianity were executed. According to later chroniclers, these successes, particularly the sack of Anazarbus, impressed even the Arabs.