Islam is one of the world’s great religions, one of history’s most important civilizations, and one of the foundational cultures of the West. During Islam’s first five hundred years, from the seventh through the twelfth centuries, this new religion created the most innovative and influential civilization on earth, an essential bridge between antiquity and modernity. For many more centuries the Islamic world remained a center of learning, wealth, luxury and sophistication, envied and imitated by its neighbors. By the sixteenth century, when parts of the Islamic world had begun to be eclipsed by the West as a military, economic and social power, Islam had changed just about everything. The books we read, the music we play, the words we speak, the numbers we count, the clothes we wear, the food we eat, the science we depend on—all were shaped, at least in part, by Islam.