Extraordinary new discoveries suggest that civilization as we know it began 12,000 years ago. Between the Middle Eastern rivers of Tigris and Euphrates, the world's first cities, Ur and Babylon, were built out of mudbrick and grew into vast empires. See how recent excavations are rewriting the first chapter in man's long journey to civilization. Then track how these ancient societies expanded to Africa, Europe, and ultimately became inexorably linked with the Western world, thanks, in large part, to the conquests of Alexander the Great.

Mecca, according to Muslim tradition, is the city where the Prophet Muhammad received God's message and Islam was born. Over 1,400 years later, the religion has more than 1.5 billion worshipers. But how did it become the fastest-growing religion on Earth? Follow Islam's amazing journey as we explore the cultural heritage of its first converts, nomadic Arab tribes who banded together under this new faith. United, they became a global power that transformed the Middle East, and the world, forever.

Excavations in southern Turkey have recently uncovered evidence of the world's first sacred temples, providing amazing insights into the birth of organized religion. In this episode, we explore man's creation of a belief system to make sense of our bewildering world. Then we'll reveal how the pantheon of pagan gods that ruled in Mesopotamia, Egypt, Greece, and Rome were ultimately overthrown by a revolutionary idea: monotheism. Discover the story of how the belief in one God was born in the East and how it came to dominate the Western world.