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.

Alex Gibney explores the charged issue of pedophilia in the Catholic Church, following a trail from the first known protest against clerical sexual abuse in the United States and all the way to the Vatican. The title is derived from the Latin phrase "mea maxima culpa". It is taken from the Confiteor that is part of the Roman Catholic Mass. It translates into English as "My most grievous fault" The film examines the abuse of power in the Catholic Church system through the story of four deaf men who set out to expose the priest who abused them during the mid-1960s. Each of the men brought forth the first known case of public protest against clerical sex abuse, which later lead to the sex scandal case known as the Lawrence Murphy case. Through their case the film follows a cover-up that winds its way from the row houses of Milwaukee, Wisconsin, through Ireland's churches, all the way to the highest office of the Vatican.

Marcus du Sautoy uncovers the patterns that explain the shape of the world around us. Starting at the hexagonal columns of Northern Ireland's Giant's Causeway, he discovers the code underpinning the extraordinary order found in nature - from rock formations to honeycomb and from salt crystals to soap bubbles. Marcus also reveals the mysterious code that governs the apparent randomness of mountains, clouds and trees and explores how this not only could be the key to Jackson Pollock's success, but has also helped breathe life into hugely successful movie animations.

Over one billion Christians look to Rome, more than half of all Christians on the planet. But how did a small Jewish sect from the backwoods of 1st-century Palestine, which preached humility and the virtue of poverty, become the established religion of western Europe - wealthy, powerful and expecting unfailing obedience from the faithful? Amongst the surprising revelations, Professor MacCulloch tells how confession was invented by monks on a remote island off the coast of Ireland, and how the Crusades gave Britain the university system. Above all, it is a story of what can be achieved when you have friends in high places.

Professor Robert Bartlett explores the impact of the Norman conquest of Britain and Ireland. Bartlett shows how William the Conqueror imposed a new aristocracy, savagely cut down opposition and built scores of castles and cathedrals to intimidate and control. He also commissioned the Domesday Book, the greatest national survey of England that had ever been attempted. England adapted to its new masters and both the language and culture were transformed as the Normans and the English intermarried. Bartlett shows how the political and cultural landscape of Scotland, Wales and Ireland were also forged by the Normans and argues that the Normans created the blueprint for colonialism in the modern world.

Julian Richards investigates the impact of the Vikings in Britain. This edition focuses on the archaeological trail left by the Vikings as they travelled from Norway along the sea road to Dublin. Settlements, a boat burial and evidence of trading have been discovered on the Scottish isles, and silver hoards found in Ireland suggest that Dublin was not only wealthy and important, but also a centre for trade in slaves.