Exacerbated by lack of supplies, this disease caused much loss of life both among men and beasts, while the army also suffered many casualties from the Byzantines' attacks. So bad was the situation that the 10th-century Arab Christian historian Agapius reports that many of Sulayman's soldiers even defected to the Byzantines and converted to Christianity. These failures were compounded by a Byzantine counter-attack shortly after which targeted Malatya. The city was saved, although Hisham himself had to take the field with whatever forces he could assemble; nevertheless, this attack, the first after many years of Byzantine passivity, signalled the shifting balance of power in the region. In the same year, Sulayman received and carried out his father's orders to execute all Byzantine prisoners, after a false report reached the Caliph that the Byzantines had executed their own Muslim prisoners. In 742 however, taking advantage of the Byzantine civil war between the usurper Artabasdos and Constantine V (r. 741–775), Sulayman led another raid which reached as far as Paphlagonia undisturbed and took many prisoners. In 743, Hisham died, and Sulayman's cousin al-Walid II took power. Walid, jealous of Sulayman's popularity, had him flogged and imprisoned, an act which aroused considerable opposition and cost Walid much of the initial good will that he had enjoyed at his accession. In spring 744, a coup in Damascus deposed Walid, who was absent from the capital and was killed soon after, and replaced him with Yazid III. The Arabs of the region around Homs, still loyal to Walid, rose up and marched on Damascus with the intention of installing as caliph a descendant of the Sufyanid branch of the Umayyad clan, Abu Muhammad al-Sufyani, but Sulayman was released from prison and defeated them. The turmoil did not subside however: when Yazid died in September 744, the powerful and ambitious governor of northern Mesopotamia ("Jazira"), Marwan ibn Muhammad, rose up against his successor Ibrahim ibn al-Walid, supported mostly by the Qaysis of the Jazira and northern Syria. Initially, Marwan did not claim the caliphate for himself, but proclaimed his intention to restore the throne to the two imprisoned sons of Walid II. Marwan's advance was met south of Baalbek by Sulayman with the "Dhakwāniyya".