By the time of the arrival of Islam in the early seventeenth century CE, what we now call the Middle East was divided between the Persian and Byzantine empires. But with the spread of this new religion from Arabia, a powerful empire emerged, and with it a flourishing civilization and a glorious golden age. Given how far back it stretches in time, the history of the region -- and even of Iraq itself -- is too big a canvas for me to paint. Instead, what I hope to do in this book is take on the nonetheless ambitious task of sharing with you a remarkable story; one of an age in which great geniuses pushed the frontiers of knowledge to such an extent that their work shaped civilizations to this day.