The failure of Islam to take the city in 717 had far-reaching consequences. The collapse of Constantinople would have opened the way for a Muslim expansion into Europe that might have reshaped the whole future of the West; it remains one of the great “What ifs” of history. It blunted the first powerful onslaught of Islamic jihad that reached its high watermark fifteen years later at the other end of the Mediterranean when a Muslim force was defeated on the banks of the Loire, a mere 150 miles south of Paris.
