Civilizations collide when the transcendental values that govern them are used to define identity. During the Crusades, the Christian belief that God was immanent in the person of Jesus Christ collided with the Islamic vision that God is transcendent. For the Christian world all that was holy and venerable was embodied in the Cross of the Holy Sepulcher on which Jesus is believed to have been...

The Murabitun revolution was one of the few genuine mass movements in Islamic history. Growing out of the womb of Africa, it engulfed two continents and played a decisive role in historical developments in Africa and Spain alike. As a mass movement, European as well as Muslim scholars have studied it extensively. Ibn Khaldun used it as a basis for his theory of the rise and fall of...

The Qur’an bestows upon humankind the keys to the heavens and the earth (“Do you not see that God has made subject to thee all that is between the heavens and the earth”, Qur’an, 31:20). In the golden age of their history, Muslims used these keys to unlock the secrets of nature and they created a civilization that was the marvel of the world. Then, they overreached...

A divided Islamic world offered feeble resistance to the Crusaders who consolidated their hold on the eastern Mediterranean and imposed their fiefdoms on the region. The Seljuks, preoccupied with defending their eastern flank against the Afghan Ghaznavids, had thinned out their western defenses. The pagan Turkish tribes across the Amu Darya on the northeastern frontiers were a constant menace....