Today, August 15, marks the anniversary of Constantinople’s victory over Muslim invaders in what historians commonly call the “Second Siege of Byzantium,” 717–18. Prior to this massive onslaught, the Muslims had been hacking away at the domains of the Byzantine empire for nearly a century. The Muslims’ ultimate goal was the conquest of Constantinople — for both political and religious reasons.
Politically, Islam had no rival but the “hated Christians” of Byzantium, known by various appellations — including al-Rum (the Romans), al-Nassara (the Nazarenes), and, most notoriously, al-Kilab (the “dogs”). The eastern Sasanian Empire had already been vanquished, and Persia subsumed into the caliphate. Only the “worshippers of the cross” — as they were, and still are, disparagingly known — were left as contenders over the eastern Mediterranean basin.
More important, Constantinople — from a theological perspective — simply had to fall. From the start, Islam and jihad were inextricably linked. The jihad, or “holy war,” which took over Arabia and Persia, followed by Syria, Egypt, and all of North Africa — all formerly Byzantine territory — was considered a religious obligation, or, as later codified in sharia law, a fard kifaya: a communal obligation on the body of believers, to be adhered to and fulfilled no less than the Five Pillars of Islam. As the famous 14th-century Muslim historian Ibn Khaldun put it: “In the Muslim community, the jihad is a religious duty, because of the universalism of the Muslim mission and the obligation to convert everybody to Islam either by persuasion or by force. . . . Islam is under obligation to gain power over other nations.”
This concept of jihad as institutionalized holy war was first articulated and codified into Islam’s worldview by “warrior-theologians” (mujahidin-fuqaha) living and fighting along the Byzantine-Arab frontier (such as the mujahid Abdallah bin Mubarak, author of the seminal work Kitab al-Jihad or “Book of Jihad”).
The prevalent view was that, so long as Constantinople stood, the Cross would defy the Crescent. This is a literal point: Symbols played a great role in these wars. Less than a century earlier, at the pivotal battle of Yarmuk (636), where the Muslims crushed the Byzantines, leading to the conquest of Syria, one Muslim complained to the caliph, saying, “The dog of the Romans [Emperor Heraclius] has greatly frustrated us with the ubiquitous presence of the cross!”
Indeed, one cannot overemphasize the religious nature of these wars — which, if still codified in Islam’s sharia, has become all but alien to a Western epistemology that tends to cynically dismiss the role of faith. That the primary way of identifying oneself in the old world was based on religious affiliation — not race, ethnicity, or nationality, all modern concepts — is indicative of the central role of faith. Even useful terms such as “Byzantines” are ultimately anachronistic; “Byzantines” identified themselves first and foremost as “Christians.”
For these reasons, the conquest of Constantinople would take on increasingly apocalyptic proportions in Islamic literature. Ever since the Muslim prophet Mohammed sent a message in 628 to the Byzantine emperor Heraclius, summoning him to Islam, with the famous assertion, aslam taslam — that is, “submit [become Muslim], and you will have peace” — and the summons was refused, Constantinople became Islam’s arch-enemy. Mohammed even prophesied that the Christian capital would — indeed, must — fall to Islam, with blessings and rewards to the Muslim(s) fulfilling this prophecy. Fall the great city would — but not for some 800 years, in 1453, giving an inchoate Europe the needed time to mature, strengthen, and unify.
Beginning with Mohammed’s participation at the Battle of Tabuk (630), recorded in the Koran, Muslims had been harrying the Byzantines for decades, closing in on Constantinople. With the coming of the Umayyad dynasty (660) — which also saw the end of the first fitna (Muslim “civil war”), resulting in the Sunni-Shia split — Islam’s seat of power moved from Medina to recently conquered Damascus, mere miles from the prize of Constantinople.
By the early 700s, the Muslim conquests were slowing down. There were several “disaffected” parties in the Muslim camp — particularly the losers of the first fitna, the Kharijites and Shia, the former a particularly ruthless sect. To prevent another civil war from erupting, a major campaign against the common infidel enemy was in order.