Islam liberated men and women from the shackles of slavery and made them masters of the world. The history of the Mamlukes illustrates this observation. In the 9th and 10th centuries, there was a brisk slave trade down the Volga River, near the Caspian Sea. The Vikings raided Europe with unrelenting ferocity in search of booty and slaves. Eastern Europe, fossilized as it was between...

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....