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.

Dr Francesca Stavrakopoulou asks whether the ancient Israelites believed in one God as the Bible claims. She puts the Bible text under the microscope, examining what the original Hebrew said, and explores archaeological sites in Syria and the Sinai which are shedding new light on the beliefs of the people of the Bible. Was the God of Abraham unique? Were the ancient Israelites polytheists? And is it all possible that God had another half?

Is God worshipped in other worlds, across the cosmos? How might alien deities differ from our own? The answer may lie buried on Earth. Animal behaviorists are testing elephants and finding them capable of having spiritual thoughts. Artificial intelligence researchers are building enlightened robots that contemplate the divine. Meanwhile, cosmologists are looking for universal equations that could replace God. Have advanced aliens discovered everything there is to know about the universe? Or are they looking to a higher power for answers?

The self-proclaimed 'Islamic State' is a jihadi militia active in the north and east of Syria, and in the west of Iraq, which has shocked the world with its cinematic staging of horrific acts of violence and its unexpected advances towards statehood. But why could IS expand so rapidly?

Dr Thomas Dixon delves into the BBC's archive to explore the troubled relationship between religion and science. From the creationists of America to the physicists of the Large Hadron Collider, he traces the expansion of scientific knowledge and asks whether there is still room for God in the modern world. He looks at what happens when new scientific discoveries start to explain events that were once seen as the workings of God, and explains how some of our most famous scientists have seen God in the grandest laws of the universe. Finally, he finds intriguing evidence from brain science which hints that belief in God is here to stay.

In this documentary we moved to Ancient Egypt to learn their vision of the world, life and death, gods and magic. For the ancient Egyptians, the Nile was the main connection between their lives and an infinite supply of provisions. But its waters hid an underworld of darkness and mystery for its first settlers. The Nile was one the spiritual paths that combined life and death, the real world and the underworld.