Sulayman is first attested as leading the northern summer expedition against Byzantine-held Anatolia in 732, and again in 735, 736 and in 737, but on neither campaign does he seem to have accomplished anything of note. In 738 however, he sacked a Byzantine fortress called Sideroun taking many prisoners, including its commander, Eustathios. In 740, he was placed in overall charge of the exceptionally large campaign prepared for that year, which according to the chronicle of Theophanes the Confessor totalled 90,000 men. Two task forces were sent first, one of 10,000 lightly armed men under al-Ghamr ibn Yazid which was to raid the western coast of Anatolia, and 20,000 under Abdallah al-Battal and al-Malik ibn Su'aib who followed after towards Akroinon. The main force of some 60,000, under Sulayman, raided Cappadocia with Tyana as their target. Sulayman failed to take the city, and returned home after plundering the countryside. The second task force however suffered a major defeat at the Battle of Akroinon, losing some two thirds of its men, as well as its commanders. In the next year, Sulayman again led the summer campaign, and was again unsuccessful: while his forces besieged a Byzantine fortress, a disease struck their camp. 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, Sulayman led another raid which reached as far as Paphlagonia undisturbed and took many prisoners.
Civil wars
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, 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. This was his personal army, 5,000 or more strong, maintained from his own funds and estates but recruited mostly from the mawālī. In the ensuing battle, Marwan was victorious. Sulayman retreated to Damascus, where he ordered the execution of Walid II's sons, and then fled, together with Ibrahim, to Palmyra. Soon however they came before Marwan and surrendered themselves. Marwan's accession to the Caliphate remained contested both in Syria and in southern Mesopotamia. After crushing a Syrian revolt in 745, Marwan formed an army of Syrian troops to send into Iraq, but they rebelled on their way and accepted Sulayman as their leader. The rebel army took Qinnasrin, but were soon after defeated by Marwan. Although much of his army survived and withdrew to Homs under the command of his brother Sa'id, Sulayman fled from Homs to Palmyra and then to Kufa. There he entered the service of al-Dahhak ibn Qays al-Shaybani, the leader of the Mesopotamian Kharijites who, taking advantage of Marwan's preoccupation with the prolonged siege of Homs, had claimed the caliphate. After taking Homs in early 746 however, Marwan marched against Dahhak and defeated and killed him in battle at Kafartuta. The rebels then withdrew across the Tigris upon Sulayman's advice, escaping destruction for the time being. In 747 however, Marwan and his lieutenant Yazid ibn Hubayra were able to defeat the Kharijite remnants and consolidate their control of Iraq, while the surviving prominent rebels fled east; Sulayman himself fled to India along with Mansur ibn Jumhur, where he later died.
