Battle of Tours (a picture is worth a thousand words)
On October 10, 732 Muslim forces under Abd-al-Rahman advanced north from al-Andalus (Spain) and were defeated by Charles Martel (grandfather of Charlemagne) at the Battle of Tours. Most (not all) historians agree that the significance of the battle for Western history cannot be diminished:
A victorious line of march had been prolonged above a thousand miles from the rock of Gibraltar to the banks of the Loire; the repetition of an equal space would have carried the Saracens to the confines of Poland and the Highlands of Scotland; the Rhine is not more impassable than the Nile or Euphrates, and the Arabian fleet might have sailed without a naval combat into the mouth of the Thames. Perhaps the interpretation of the Koran would now be taught in the schools of Oxford, and her pulpits might demonstrate to a circumcised people the sanctity and truth of the revelation of Mahomet.--GibbonRead the rest here.