The year is 632 A.D., and Muslim hordes have set their sights on the Mideast and North Africa -- the old Christian world. And the Caliphate, as the Islamic realm is called, will not be denied. Syria and Iraq fall in 636. Palestine is next in 638. And Byzantine Egypt and North Africa, not even Arab lands, are conquered by 642 and 709, respectively. Then, just two years later, the Muslims cross the Strait of Gibraltar and enter Iberia (now Spain and Portugal). The invasion of Europe has begun.

And the new continent seems no impediment to Islam. After vanquishing much of Visigothic Iberia by 718, the Muslims cross the Pyrenees Mountains into Gaul (now France) and move northward. Now it is 732, and they are approaching Tours, a mere 126 miles from Paris. The Western world -- what's left of Christendom -- could very well be on its way to extinction.

Europe is currently easy prey, comprising disunited, often belligerent kingdoms and duchies recently decimated by plague. In contrast, the Islamic world is a burgeoning civilization; so much so, in fact, that it views the Europeans as barbarians. The Muslims also command enormous battle-hardened military forces and have enjoyed almost unparalleled breadth and rapidity of conquest, while Europe no longer has standing armies. It largely relies on peasants to do its fighting, men available only when crops aren't beckoning. Yet the Christian Europeans do have one great asset: Charles of Herstal, grandfather of Charlemagne.

Sensing the coming storm as early as 721, Charles realized he was going to need a professional, well-oiled fighting force if he was to tackle the Moorish wave washing across Christendom. So, using Catholic Church resources, he set out to train just such an army. And now, 11 years later, it will be put to the ultimate test.

With a horde of 80,000 men, the Muslims once again start moving north in 732 under the leadership of Emir Abdul Rahman Al Ghafiqi. And after defeating Odo the Great and sacking his Duchy of Aquitaine, there is nothing standing between Al Ghafiqi and Paris -- except Charles of Herstal and his Frankish and Burgundian army. The two leaders would lock horns in October, on a battlefield between the towns of Tours and Poitier.

When the fateful day arrives, Al Ghafiqi is shocked by what lies before him. The "barbarians" have mustered a force the size of which he isn't used to seeing in these European backwaters. He nonetheless enjoys a great advantage, outnumbering the Christians by perhaps as much as two to one and possessing heavy cavalry, while his adversaries are limited to infantry. The outcome should still be favorable.

But Charles routs the Muslim forces, stopping their advance into Europe cold. He will eventually chase them back across the Pyrenees Mountains, saving Gaul -- and perhaps all of Western civilization -- from the sword of Islam. His miraculous 732 victory becomes known as the Battle of Tours (or Poitier), and it wins him the moniker "Martellus." Thus do we now know him as Charles Martel, which translates into Charles the Hammer.

Yet the Abode of Islam would not stop hammering Christendom. It is now 1095, and the Muslims are threatening Europe from the east. After seizing most of the Byzantine Empire's territory 400 years prior, they have now, just recently, subdued Anatolia (most of modern Turkey), thus robbing the Byzantines of the majority of their remaining land. The Muslims are now poised to move west into Greece itself or perhaps north into the Balkans -- Europe's "back door." And Byzantine emperor Alexius I in Constantinople knows that his realm is too weak to resist. What is he to do?

Alexius decides to approach the Church. Although he and current pope Urban II have been rivals, the pontiff recognizes Islamic expansion to be a clear and present danger. So he decides to address the matter at the Council of Clermont in 1095. In a rousing sermon in front of more than 650 clerics and Christian nobles, he appeals to Europeans to stop bickering amongst themselves and rally to the aid of their eastern brothers. What follows is an excerpt of his words as recorded by the Fulcher of Chartres:

Your brethren who live in the east are in urgent need of your help, and you must hasten to give them the aid which has often been promised them. For, as the most of you have heard, the Turks and Arabs have attacked them and have conquered the territory of Romania [the Greek empire] as far west as the shore of the Mediterranean and the Hellespont, which is called the Arm of St. George. They have occupied more and more of the lands of those Christians, and have overcome them in seven battles. They have killed and captured many, and have destroyed the churches and devastated the empire. If you permit them to continue thus for awhile with impunity, the faithful of God will be much more widely attacked by them. On this account I, or rather the Lord, beseech you as Christ's heralds to publish this everywhere and to persuade all people of whatever rank, foot-soldiers and knights, poor and rich, to carry aid promptly to those Christians....

And thus was born the 11th-century Hammer writ large: the Crusades.

Like Martel's campaigns before them, the Crusades were defensive actions designed to stave off Muslim aggression. Oh, this isn't what you learned in college, I know. It's not what we hear from the media. It isn't what's portrayed by Hollywood. But it is the truth. And it was explained well by Thomas Madden, Chair of the History Department at Saint Louis University. In "The Real History of the Crusades" he wrote:

The Crusades are generally portrayed as a series of holy wars against Islam led by power-mad popes and fought by religious fanatics. They are supposed to have been the epitome of self-righteousness and intolerance, a black stain on the history of the Catholic Church in particular and Western civilization in general. A breed of proto-imperialists, the Crusaders introduced Western aggression to the peaceful Middle East and then deformed the enlightened Muslim culture, leaving it in ruins.

... [But] Christians in the eleventh century were not paranoid fanatics. Muslims really were gunning for them. While Muslims can be peaceful, Islam was born in war and grew the same way. From the time of Mohammed, the means of Muslim expansion was always the sword. Muslim thought divides the world into two spheres, the Abode of Islam and the Abode of War.... In the eleventh century, the Seljuk Turks conquered Asia Minor (modern Turkey), which had been Christian since the time of St. Paul. The old Roman Empire, known to modern historians as the Byzantine Empire, was reduced to little more than Greece.

... [The Crusades] were not the brainchild of an ambitious pope or rapacious knights but a response to more than four centuries of conquests in which Muslims had already captured two-thirds of the old Christian world. At some point, Christianity as a faith and a culture had to defend itself or be subsumed by Islam. The Crusades were that defense.

And that is why I defend them today. No, they weren't perfectly executed, nor could they achieve all their objectives any more than the Cold War truly vanquished the left. Evil is always afoot. But note that the Mideast and North Africa had more Christians than Europe at the time of the early Muslim invasions -- but no one to Crusade for them. Thus, it's easy to imagine that, were it not for our hammering medieval heroes, we could well be what the Mideast is today. And unless we shelve multiculturalism and become what those crusaders were yesterday, we may not have a tomorrow.

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