Siege of Constantinople (674–678) in the context of "Constantine IV"

The Arab–Byzantine wars or Muslim–Byzantine wars were a series of wars from the 7th to 11th centuries between multiple Arab dynasties and the Byzantine Empire. The Muslim Arab Caliphates conquered large parts of the Christian Byzantine empire and unsuccessfully attacked the Byzantine capital of Constantinople. The frontier between the warring states remained almost static for three centuries of frequent warfare, before the Byzantines were able to recapture some of the lost territory.

The conflicts began during the early Muslim conquests under the expansionist Rashidun Caliphate, part of the initial spread of Islam. In the 630s, Rashidun forces from Arabia attacked and quickly overran Byzantium's southern provinces. Syria was captured in 639 and Egypt was conquered in 642. The Exarchate of Africa was gradually captured between 647 and 670. From the 650s onwards, Arab navies entered the Mediterranean Sea, which became a major battleground. Both sides launched raids and counterraids against islands and coastal settlements. The Rashidun were succeeded by the Umayyad Caliphate in 661, who over the next fifty years captured Byzantine Cyrenaica and launched repeated raids into Byzantine Asia Minor. Umayyad forces twice placed Constantinople under siege, in 674 to 678 and 717 to 718, but failed to seize the heavily fortified Byzantine capital.

Yazid ibn Mu'awiya ibn Abi Sufyan (c. 646 – 11 November 683), commonly known as Yazid I, was the second caliph of the Umayyad Caliphate, ruling from April 680 until his death in November 683. His appointment by his father Mu'awiya I (r. 661–680) was the first hereditary succession to the caliphate in Islamic history. His caliphate was marked by the death of Muhammad's grandson Husayn ibn Ali and the start of the crisis known as the Second Fitna.

During his father's caliphate, Yazid led several campaigns against the Byzantine Empire including an attack on the Byzantine capital, Constantinople. Yazid's nomination as heir apparent in 676 CE (56 AH) by Mu'awiya was opposed by several Muslim grandees from the Hejaz region, including Husayn and Abd Allah ibn al-Zubayr. The two men refused to recognize Yazid following his accession and took sanctuary in Mecca. When Husayn left for Kufa in Iraq to lead a revolt against Yazid, he was killed with his small band of supporters by Yazid's forces in the Battle of Karbala. Husayn's death caused resentment in the Hejaz, where Ibn al-Zubayr called for a consultative assembly to elect a new caliph. The people of Medina, who supported Ibn al-Zubayr, held other grievances toward the Umayyads. After failing to gain the allegiance of Ibn al-Zubayr and the people of the Hejaz through diplomacy, Yazid sent an army to suppress their rebellion. The army defeated the Medinans in the Battle of al-Harra in August 683 and the city was plundered. Afterward, Mecca was besieged for several weeks until the army withdrew as a result of Yazid's death in November 683. The Caliphate fell into a nearly decade-long civil war, ending with the establishment of the Marwanid dynasty (the Umayyad caliph Marwan I and his descendants).