Professor Diarmaid MacCulloch - one of the world's leading historians - reveals the origins of Christianity and explores what it means to be a Christian. In the first episode, he overturns the familiar story that it all began when the apostle Paul took Christianity from Jerusalem to Rome. Instead, he shows that the true origins of Christianity lie further east, and that at one point it was poised to triumph in Asia, maybe even in China. The headquarters of Christianity might well have been Baghdad not Rome, and if that had happened then Western Christianity would have been very different.

The tale of one of China's most famous dynasties begins with the amazing story of Hongwu, a peasant rebel who founded one of greatest eras in Chinese history. The film takes us to his great capital Nanjing, with its 21 miles of walls, each brick stamped with the name of the village that made it. Following the trail, we go to the Bao family village and see the villagers act a Ming murder story.
Like many authoritarian states, the Ming were obsessive about architecture. We see the giant fortifications of the Great Wall, the ritual enclaves of the Forbidden City in Beijing and travel with bargeman Mr Hu down the Grand Canal, China's great artery of commerce right up to the present day. We then hear about Admiral Zheng He's voyages to Africa and the Gulf decades before Columbus, watch the construction of an ocean-going wooden boat 250ft long, and hitch a ride on a replica Ming junk in the South China Sea.
As state prosperity grew, so did a rising middle class. Wood looks at Ming culture in Suzhou, the 'Venice of China'. Staying in a merchant's house, he discovers the silk, ceramic and lacquer-making industries, and visits one of the most beautiful gardens in the city. Then on to Macao and the arrival of Jesuit missionary Matteo Ricci, who hoped to convert China to Christianity. In the cathedral in Beijing, we learn more about these fateful exchanges with the west. Finally in Shaoxing, we visit the house of the 'Ming Proust' and at grassroots the Zhao family in Fujian where the film ends in an elegiac mood with the fall of the Ming in 1644.

Professor Robert Bartlett explores the impact of the Normans on southern Europe and the Middle East. The Normans spread south in the 11th century, winning control of southern Italy and the island of Sicily. There they created their most prosperous kingdom, where Christianity and Islam co-existed in relative harmony and mutual tolerance. It became a great centre of medieval culture and learning. But events in the Middle East provoked the more aggressive side of the Norman character. In 1095, the Normans enthusiastically answered the Pope's call for holy war against Islam and joined the first crusade. They lay siege to Jerusalem and eventually helped win back the holy city from the muslims. This bloody conquest left a deep rift between Christianity and Islam which is still being felt to this day.

Can we find the Garden of Eden? Bible scholar Dr Francesca Stavrakopoulou thinks so. In the final episode of her series re-examining conventional readings of the Bible, she argues that the Garden of Eden has nothing to do with the origins of humanity, but is rather a story concealing dramatic events about a particular figure in a particular place, two and half thousand years ago. Marshalling compelling evidence from archaeology, Islam and the Bible text itself, she identifies and visits the exact site of Eden. It's a revolutionary theory which challenges some of the most cherished preconceptions about Eden in both Christianity and western culture.

Dr. Thomas Asbridge explains how in the thirteenth century, after almost two hundred years of Holy Wars, the titanic conflict between Christianity and Islam, known to history as The Crusades, reached a decisive and shocking conclusion – a chapter that despite its drama has been virtually forgotten. He explains how, in the end, the fate of the Holy Land was decided not on the hallowed ground of Jerusalem, but in Egypt; and how the ultimate outcome of the Crusades was dictated not by Christians, but by the Mongol successors to Genghis Khan, and by a Muslim slave – a fearsome warrior whose story is now all but lost to western history.

In the third episode of the series, Morgan Freeman examines different faiths' concepts of God, discovering how monotheism began in Egypt and Israel and allowing a neuroscientist to examine his own brain.