Byzantine-Muslim relations in the Heraclian Dynasty (610-711)

The Heraclius Dynasty (610-711) represents a critical period of political, social, cultural and religious transformations in the history of the Byzantine Empire. When Heraclius, son of the Exarch of Carthage, overthrew his predecessor Phokas and seized the Byzantine throne in 610, the Heraclian Dynasty began. Emperor Heraclius won the long and difficult wars with the Sassanids in 628, one of the most important threats he faced after taking the throne. However, this military success was not enough for the empire to take a deep breath. Soon after, the empire was confronted with the Islamic State, which emerged in the south, in the Arabian Peninsula, and gained political unity in a short time. The relations of the Heraclius Dynasty with the Muslims started during the reign of Prophet Muhammad (peace be upon him). Contacts, which were at the diplomatic level in the beginning, turned into military conflicts in time. The relations between the two states continued during the reign of Heraclius' grandson Constans II (641- 668). During the reign of Constans, the first caliph Abu Bakr (632-634) and his successor Umar (634- 644) were at the head of the Islamic State. While Byzantium's land struggles with the Muslims continued, the empire lost its superiority in the Eastern Mediterranean in the first major naval battle (Zâtüssavârî) in 655. After Emperor Constantine II, his son Constantine IV (668-685) took the throne. During the reign of Constantine IV, relations between the Umayyads, under the leadership of Mu'awiya, and Byzantium became more conflicted. During this period, Anatolian lands were frequently targeted by Muslim raids and the region was under constant military pressure. The city most affected by Muslim attacks was Constantinople, the capital of the Byzantine Empire. Between 668-679, the city was subjected to Muslim sieges from land and sea. In the last naval siege, the Muslims were heavily defeated thanks to the Byzantine naval power and the use of the fire burning on the water known as 'Grajuva'. After Constantine IV, Justinian II (685-695/705-711) took over the dynasty in 685. Justinian II, the last representative of the Heraclius Dynasty, ascended the Byzantine throne twice. During this period, intense diplomatic contacts with the Umayyads as well as military struggles between the two states continued. In this study, the relations between Byzantium and the Muslims during the Heraclius Dynasty are analysed in a multidimensional manner in the context of military conflicts, diplomatic initiatives and cultural interactions.