When did the Desert Meet the West?

In the year 622 CE, a man fled into the desert, his life hanging by a thread. Muhammad, a merchant-turned-prophet, had spent over a decade preaching monotheism in Mecca, but his message of submission to Allah had made powerful enemies. The city’s elite, fearing his growing influence, sought to kill him. In the dark of night, Muhammad and his followers escaped to Yathrib, later known as Medina. This event, called the Hijra, marked not only Muhammad’s survival but also the beginning of a new era. Within a decade, his message would unite the warring Arab tribes under a single faith: Islam. Within a century, his followers would build an empire stretching from Persia to Spain, forever changing the world.

That expansion reached a dramatic turning point in 711 CE, when an army of Arab and Berber warriors, led by the general Tariq ibn Ziyad, crossed the Strait of Gibraltar and marched into the Iberian Peninsula. At the Battle of Guadalete, the Visigothic King Roderic was defeated, and his kingdom collapsed. Spain—once a Roman province, then a Visigothic realm—became Al-Andalus, part of the ever-growing Islamic world. Within a few years, most of the Iberian Peninsula was under Muslim control, and the new rulers brought with them a civilization of dazzling architecture, advanced science, and a fusion of Arab, Berber, and Iberian cultures.

But history is rarely one-directional. In 720 CE, a Christian resistance began to take shape in the rugged mountains of Asturias, led by a man named Pelayo. At the Battle of Covadonga, his small force managed to repel an advancing Muslim army. At the time, the battle seemed insignificant compared to the vast Islamic conquests. But in retrospect, it was the spark that ignited the centuries-long Reconquista, the slow Christian reconquest of Spain that would take nearly 800 years to complete.

Meanwhile, the Arab advance was pushing deeper into Europe. By 732 CE, an army of Muslim cavalry reached the heart of Frankish territory, threatening the very foundations of Christian Europe. But at the Battle of Tours, the Frankish leader Charles Martel stood in their way. His disciplined infantry, armed with heavy armor and close combat tactics, halted the Muslim advance, pushing them back south. For the Franks, it was a divine victory, a moment that would later be mythologized as the event that saved Christendom. But for the Arabs, it was merely a setback—their empire still stretched from the Atlantic to Central Asia.

Yet, even the greatest empires have their limits. In 740 CE, the Arab armies launched a massive assault on Constantinople, the beating heart of the Byzantine Empire. If the city fell, the last remnants of the Roman world would vanish, and Islam would extend into the Balkans centuries earlier than it eventually did. But the Byzantines had an ace up their sleeve—Greek fire, a terrifying incendiary weapon that could burn even on water. The flames devoured the Arab fleet, and Constantinople stood firm. The Arabs retreated, and though their empire remained vast, its expansion into Europe had reached its high-water mark.

Had things played out differently—had Charles Martel lost at Tours, had Constantinople fallen in 740—Europe might have looked very different today. The Islamic world had brought mathematics, medicine, and astronomy to new heights, and its culture and science would eventually flow into medieval Europe through Spain and Sicily. But history took another path. The Islamic empire stabilized in Iberia and North Africa, while Christian Europe, once fractured, would slowly consolidate into powerful kingdoms.