Mohammedanism and Peace
September, A.D. 622.
"The Prophet Mohammed had taken flight with a few followers from the hostile city of Mecca to friendly Medina, thereby marking the starting point for the whole Muslim era; and just five years afterwards, in 633, the armies of Islam would begin the advance that was to take them, in the course of a single century, to within 150 miles of Paris and to the very gates of Constantinople, Christendom’s most formidable rival - and for the next thousand years its most implacable enemy - was already born, and would soon be on the march.
Until the second quarter of the seventh century, the land of Arabia was terra incognita to the Christian world. Remote and inhospitable,productive of nothing to tempt the sophisticated merchants of the West, it had made no contribution to civilization and seemed unlikely ever to do so. Its people, insofar as anyone knew anything about them, were presumed to be little better than savages, periodically slaughtering each other in violent outbreaks of tribal warfare, falling mercilessly upon any traveller foolhardy enough to venture among them, making not the slightest attempt towards unity or even stable government.
Apart from a few scattered Jewish colonies around the coast and in Medina and a small Christian community in the Yemen, the overwhelming majority practised a sort of primitive polytheism which, in the city of Mecca - their commercial centre - appeared to be somehow focused on the huge black stone that stood in their principal temple, the Ka’aba. Where the outside world was concerned they showed no interest, made no impact and certainly posed no threat.
Then, in the twinkling of an eye, all was changed. In 633, showing discipline and singleness of purpose of which they had previously given no sign and which was therefore totally unexpected by their victims, they suddenly burst out of Arabia. After three years they had taken Damascus; after five, Jerusalem; after six, all Syria. Within a decade, Egypt and Armenia had alike fallen to the Arab sword; within twenty years, the whole Persian Empire; within thirty, Afghanistan and most of the Punjab.
Then, after a brief interval for consolidation, the victorious armies turned their attention to the West. In 711, having occupied the entire coast of North Africa, they invaded Spain; and by 732, less than a century after their first eruption from their desert homeland, they had crossed the Pyrenees and driven north to the banks of the Loire - where, after a week-long battle, they were checked at last.”
— Byzantium Vol I p.302
by John Julius Norwich