In Western history

The first wave of real " modern" historians, especially scholars on Rome and the medieval period, such as Edward Gibbon, contended that had Charles fallen, the Umayyad Caliphate would have easily conquered a divided Europe. Gibbon famously observed:

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.

Nor was Gibbon alone in lavishing praise on Charles as the savior of Christiandom and western civilisation. H.G. Wells in his A Short History of the World said in Chapter XLV " The Development of Latin Christendom: "

The Moslim when they crossed the Pyrenees in 720 found this Frankish kingdom under the practical rule of Charles Martel, the Mayor of the Palace of a degenerate descendant of Clovis, and experienced the decisive defeat of Poitiers (732) at his hands. This Charles Martel was practically overlord of Europe north of the Alps from the Pyrenees to Hungary. He ruled over a multitude of subordinate lords speaking French-Latin, and High and Low German languages.

Gibbon was echoed a century later by the Belgian historian Godefroid Kurth, who wrote that the Battle of Poitiers " must ever remain one of the great events in the history of the world, as upon its issue depended whether Christian Civilisation should continue or Islam prevail throughout Europe."

German historians were especially ardent in their praise of Charles Martel; Schlegel speaks of this " mighty victory", and tells how " the arm of Charles Martel saved and delivered the Christian nations of the West from the deadly grasp of all-destroying Islam." Creasy quotes Leopold von Ranke's opinion that this period was:

One of the most important epochs in the history of the world, the commencement of the eighth century, when on the one side Mohammedanism threatened to overspread Italy and Gaul, and on the other the ancient idolatry of Saxony and Friesland once more forced its way across the Rhine. In this peril of Christian institutions, a youthful prince of Germanic race, Karl Martell, arose as their champion, maintained them with all the energy which the necessity for self-defence calls forth, and finally extended them into new regions.

The German military historian Hans Delbruck said of this battle " there was no more important battle in the history of the world." (The Barbarian Invasions, page 441.) Had Charles Martel failed, Henry Hallam argued, there would have been no Charlemagne, no Holy Roman Empire or Papal States; all these depended upon Charles's containment of Islam from expanding into Europe while the Caliphate was unified and able to mount such a conquest. Another great mid era historian, Thomas Arnold, ranked the victory of Charles Martel even higher than the victory of Arminius in its impact on all of modern history: " Charles Martel's victory at Tours was among those signal deliverances which have affected for centuries the happiness of mankind." Louis Gustave and Charles Strauss in Moslem and Frank; or, Charles Martel and the rescue of Europe said " The victory gained was decisive and final, The torrent of Arab conquest was rolled back and Europe was rescued from the threatened yoke of the Saracens." (page 122)

Charles Oman, in his History of the Art of War in the Middle Ages, concludes that:

At Poitiers the Franks fought as they had done two hundred years before at Casilinum, in one solid mass, without breaking rank or attempting to maneuver. Their victory was won by the purely defensive tactics of the infantry square; the fanatical Arabs, dashing against them time after time, were shattered to pieces, and at last fled under shelter of night. But there was no pursuit, for Charles had determined not to allow his men to stir a step from the line to chase the broken foe. [I, 58]

Adolf Hitler says in Hitler's Table Talk (August 28, 1942, midday):

Had Charles Martel not been victorious at Poitiers -already, you see, the world had already fallen into the hands of the Jews, so gutless a thing Christianity! -then we should in all probability have been converted to Mohammedanism, that cult which glorifies the heroism and which opens up the seventh Heaven to the bold warrior alone. Then the Germanic races would have conquered the world. Christianity alone prevented them from doing so."

John H. Haaren says in Famous Men of the Middle Ages:

The battle of Tours, or Poitiers, as it should be called, is regarded as one of the decisive battles of the world. It decided that Christians, and not Moslems, should be the ruling power in Europe. Charles Martel is especially celebrated as the hero of this battle.” John Bagnell Bury, writing at the beginning of the 20th century, said " The Battle of Tours… has often been represented as an event of the first magnitude for the world’s history, because after this, the penetration of Islam into Europe was finally brought to a standstill.

But, as will be seen below, today’s historians are very clearly divided on the importance of the battle, and where it should rank in the signal moments of military history.