Wood travels through war-torn Afghanistan, crossing the Oxus River into Central Asia and the Silk Road city of Samarkand where, in a drunken brawl, Alexander killed the friend who had previously saved his life.

Painted over five centuries ago, Filippo Lippi's nativity is like none other: it shows the birth of Christ in a dark, wooded wilderness. There are no shepherds, kings, ox, ass – there is no Joseph. Its beauty inspired Michelangelo, Leonardo da Vinci and Botticelli. But it also conceals a deeply personal story. It was painted for Cosimo de Medici, a wealthy banker who feared that his money was dragging him straight to hell. The artist's life was equally surprising. One of the most celebrated painters of his day, Filippo Lippi was also a Carmelite friar, but he was no stranger to the temptations of the flesh, to which he frequently yielded. Shortly before painting his Adoration, he caused uproar by seducing a twenty year-old nun. His paintings rejoice not only in divine beauty, but in the beauty of women. In later times, the Adoration's history was interwoven with that of rulers and dictators. It became a bargaining chip after Napoleon's allies seized twenty merchant ships. And in the 20th century, it was hidden by the Nazis in a potassium mine, where specialist american officers, known as Monuments Men, stumbled upon it. they were now told to get it ready to be shipped out. In an unprecedented turn of events they refused. This is the only known case in the whole of the Second World War of American officers refusing an order. It was sent to the National Gallery of Art, but in 1949 Lippi's Adoration was returned to Germany.

Andrew Marr tells the story of the first empires which laid the foundations for the modern world. From the Assyrians to Alexander the Great, conquerors rampaged across the Middle East and vicious wars were fought all the way from China to the Mediterranean. But this time of chaos and destruction also brought enormous progress and inspired human development. In the Middle East, the Phoenicians invented the alphabet, and one of the most powerful ideas in world history emerged: the belief in just one God. In India, the Buddha offered a radical alternative to empire building - a way of living that had no place for violence or hierarchy and was open to everyone. Great thinkers from Socrates to Confucius proposed new ideas about how to rule more wisely and live in a better society. And in Greece, democracy was born - the greatest political experiment of all. But within just a few years, its future would be under threat from invasion by an empire in the east...

Lucy Worsley continues her journey through Russia in the footsteps of the Romanovs, the most powerful royal dynasty in modern European history. In this episode she examines the extraordinary reign of Catherine the Great, and the traumatic conflict with napoleonic France that provides the setting for the novel War and Peace. At the magnificent palace of Peterhof near St Petersburg, Lucy charts the meteoric rise of Catherine the Great, who seized the Russian throne from her husband Peter III in 1762 and became the most powerful woman in the world. Catherine was a woman of huge passions - for art, for her adopted country (she was German by birth) and for her many lovers.
Catherine expanded her empire through military victories overseas, while at home she encouraged education and introduced smallpox inoculation to Russia. But Catherine struggled to introduce deeper reforms, and the institution of serfdom remained largely unchanged. Lucy explains how this injustice fuelled a violent rebellion. Nevertheless, Catherine left Russia more powerful on the world stage than ever. But all she had achieved looked set to be undone when Napoleon invaded Russia in 1812. Lucy relives the pivotal battle of Borodino, when the Russian army finally confronted the French forces; the traumatic destruction of Moscow; and, under Catherine's grandson Alexander, the eventual victory over the French that provided the Romanov dynasty with its most glorious hour.

Hector Berrellez identifies the mysterious Cuban who interrogated Kiki Camarena: a veteran CIA operative, Felix Rodriguez, a key figure in the Iran-Contra scandal. Although warned not to take his investigation further, Hector refuses and is eventually forced into retirement. The case languishes for years, and then a new source comes forward with a shocking allegation.

American exchange student Amanda Knox is convicted and eventually acquitted for the 2007 death of another student in Italy. Was she a cold-blooded psychopath who brutally murdered her roommate or a naive student abroad trapped in an endless nightmare? Directors Rod Blackhurst (Tribeca Audience Award-winner Here Alone) and Brian McGinn (IDA Award-winner Chef's Table) and producer Mette Heide (Peabody Award-winner India's Daughter) explore the notorious case that made headlines around the world.