January 11, 630: the Prophet Muhammad conquers Mecca
Updated: Jun 1, 2021
I do not know enough about Islam, so this one might be a bit sketchy, I think.
January 11, 630. A motley army comes out of the mountains and descends upon a city in four columns. With little fighting, their leader enters the city he intends to make the holiest site of his new, radical faith. The Prophet Muhammad has entered Mecca.
Starting a new religion isn't easy; it tends to ruffle feathers. Islamic tradition holds that in 610, the archangel Gabriel commanded Muhammad to take up the mantle of prophecy. Muhammad claimed the continuation of the Judeo-Christian prophetic tradition - he counted Moses and Jesus among the holiest prophets, and his predecessors - but combined this tradition with Arabic cultural precepts and a strong revolutionary streak, all of which tended to affront the effete, worldly merchant classes of Mecca.
In 622, Muhammad fled from Mecca, his home city, with about 70 followers to nearby Yathrib in western Arabia. Yathrib, soon renamed Medina, became Muhammad's new base; from here, he waged a constant struggle against the leading families of Mecca. The unfortunate side effect of this strife was that Islam, like many other faiths, was born in struggle and bore the marks of that struggle. Muhammad's victory at Badr in 624, heavily mythologized in the hadiths that hold great weight in Islamic tradition, was probably the turning point.
Muhammad's entry into Mecca was the great achievement of his life; he would die only two years later, long before Islam became a world religion. However, the marks of Islamic conquest were already present - the tolerance for Jews and Christians as "the people of the book," widespread economic and social reform, and bitter strife between the ruling elites of the new Muslim polity.
Muhammad's eventual triumph had the profoundest consequences for world history, of course. It was an unlikely victory; there was no inherent reason that an idle merchant's son from Mecca, so far from the great empires and nations of the world, should be able to launch a movement that would spread across the globe. Then again, there was no reason a carpenter's son in backwater Palestine should have such an impact either. Muhammad, regardless of your opinion, is one of the great figures of history; only rarely has one man's personality, vision, and character written so large on the global scale and across so many centuries.
From Mecca, Muslim armies would surge forward in the 630s, overrunning Syria and Iraq; within a century they would control nations from Spain to India. It was one of the most abrupt and transforming human movements in all history.
Side note: January 11 is one of only several possible dates for this event, given the uncertainty of early Islamic dating vis-a-vis the Gregorian Calendar. Some days are just hard to find things for.
The best book for an introduction to early Islam is probably Hugh Kennedy's The Prophet and the Age of the Caliphates, 3rd Edition (London: Routledge, 2015).