Hundreds of years ago in faraway Iceland the Vikings began to write down dozens of stories called sagas - sweeping narratives based on real people and real events. But as Oxford University's Janina Ramirez discovers, these sagas are not just great works of art, they are also priceless historical documents which bring to life the Viking world. Dr Ramirez travels across glaciers and through the lava fields of Iceland to the far north west of the country to find out about one of the most compelling of these stories - the Laxdaela Saga.

A 4000-year-old body is found preserved in an Irish peat bog, in Cashel, Ireland. To scientists and historians, it could offer brand new clues to solve an ancient mystery: the hundreds of bodies found mummified in the boglands of Northern Europe. Now, will Cashel Man help prove the theory these Irish victims were ancient kings? And what clues can the bog bodies of Europe offer to explain our ancestors' most macabre tradition - ritual murder? Meanwhile, that question could be answered by the bog itself.

When ancient architects completed construction on the Great Pyramid at Giza, they left behind the greatest riddle of the engineering world—how did builders lift limestone blocks weighing an average of two and a half tons 480 feet up onto the top of the Pyramid? For centuries, adventurers and Egyptologists have crawled through every passageway and chamber of the Pyramid, measuring and collecting data in an attempt to determine how it was built. For the first time, a revolutionary theory argues that the answer may be inside the Pyramid. Architect Jean-Pierre Houdin and Egyptologist Bob Brier use 3-D software to unlock the secret.

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?

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.

The word Anunnaki means "princely seed" or "princely blood". The idea is that the Anunnaki were direct creations of Anu, who was regarded as the father and king of the gods. Ancient Aliens: "In the ancient texts of Sumeria we have descriptions of these being descending from the sky called the Anunnaki. The term Anunnaki means 'those who from the heavens came."