Byzantium, Constantinople, Istanbul. One metropolis has been the capital city of three empires - Roman, Byzantine and Ottoman. Each has brought its own faiths, beliefs and traditions, and each has left its mark on architecture, traditions and on the faith-communities who still populate this vast modern metropolis. In this series, Simon Sebag-Montefiore unveils Istanbul's strange and complex past in all its vibrancy and colour against the backdrop of this modern, living city that spans the gulf between Asia and Europe. It's a journey through the history of world faith that takes Simon from the pantheon of the Athenian Greeks through the founding of Christianity to the rise of Islam.