In Bhutan, Palin finds himself back in the land of yaks for a last look at the high Himalaya. Trekking to Chomolhari base camp he meets a nomad with a penchant for yak songs before heading down to Paro to witness the Buddhist festival or Tsechu. In a bar in Thimphu, he discusses reincarnation and the pursuit of happiness with Benji and Khendum, two of the king's cousins, and en route to Bangladesh is taken by Benji to see the rare black-neck cranes. On his journey south through Bangladesh, Michael visits the ship-breaking beaches of Chittagong and grid-locked Dhaka. He meets a man who made a fortune in Birmingham in the poultry business, and a woman who lends money only to women. On a 1920s paddle steamer he is serenaded with the words of Bengal's Shakespeare, and he completes his epic Himalayan journey aboard a fishing boat that carries him out into the Bay of Bengal and a westering sun.

In the fourth part of the series, Diarmaid MacCulloch makes sense of the Reformation, and of how a faith based on obedience and authority gave birth to one based on individual conscience. He shows how Martin Luther wrote hymns to teach people the message of the Bible, and how a tasty sausage became the rallying cry for Swiss Reformer Ulrich Zwingli to tear down statues of saints, allow married clergy and deny that communion bread and wine were the body and blood of Christ.

Ma Anand Sheela emerges as a provocative spokeswoman. The Rajneesh control Antelope city council and they establish a police force in the city. Bhagwan tells Sheela it is time to control Wasco County. As Election Day approaches, the Rajneeshees recruit thousands of homeless people to fortify their ranks.

The magnificent ancient city of pyramids at Caral in Peru is a thousand years older than the earliest known civilisation in the Americas and, at 2,627 BC, is as old as the pyramids of Egypt. Many now believe it is the fabled missing link of archaeology - a 'mother city'. If so, then these extraordinary findings could finally answer one of the great questions of archaeology: why did humans become civilised?" For over a century, archaeologists have been searching for what they call a mother city. Civilisation began in only six areas of the world: Egypt, Mesopotamia, India, China, Peru and Central America. In each of these regions people moved from small family units to build cities of thousands of people. They crossed the historic divide, one of the great moments in human history. Why? To find the answer archaeologists needed to find a mother city - the first stage of city-building. Caral, is so much older than anything else in South America that it is a clear candidate to be the mother city. It also is in pristine condition. Nothing has been built on it at all. Instead laid out before the world is an elaborate complex of pyramids, temples, an amphitheatre and ordinary houses. Scientists developed a number of theories. Some said it was because of the development of trade, others that it was irrigation. Some even today believe it was all because of aliens. Gradually an uneasy consensus emerged. The key force common to all civilisations was warfare. Crucially, there is not the faintest trace of warfare at Caral; no battlements, no weapons, no mutilated bodies. Instead, Ruth's findings suggest it was a gentle society, built on commerce and pleasure. In one of the pyramids they uncovered beautiful flutes made from condor and pelican bones. They have also found evidence of a culture that took drugs and perhaps aphrodisiacs. Most stunning of all, they have found the remains of a baby, lovingly wrapped and buried with a precious necklace made of stone beads.

This episode tells the tale of what's broadly considered China's most creative dynasty - the Song (960-1279). Michael Wood heads to the city of Kaifeng, the greatest city in the world before the 19th century. Here in Twin Dragon Alley, locals tell him the legend of the baby boys who became emperors.
He explores the ideas and inventions that made the Song one of greatest eras in world culture, helped by China's most famous work of art, the Kaifeng scroll, which shows the life of the city in around 1120. A chef makes Michael a recipe from a Song cookbook, while a guide to 'how to live happy, healthy lives for old people', published in 1085 and still in print, is discussed with local women doing their morning exercises. The Song was also a great era for scientific advance in China. Michael steers a huge working replica of an astronomical clock, made by China's Leonardo da Vinci.
Then at a crunch Chinese Premier League match, Michael tells us the Chinese invented football! The golden age of the northern Song ended in 1127, when invaders sacked Kaifeng, but they survived in the south. At their new capital, Hangzhou, Wood joins locals dancing by the West Lake, while in the countryside he meets Mr Xie with his records of 40 generations of ancestors. The final defeat of the Song took place in a naval battle in the estuary of the Pearl River in 1279. When all was lost, rather than surrender to the Mongols, a loyal minister jumped into the sea with the young boy emperor in his arms. 'So ended the glory of the Song', Wood concludes, 'but a new age would arise... as in China, it always has!'.

Artists, academics, and critics discuss the historical origins, original reception, and slow climb to critical acclaim for Eugene Delacroix's painting commemorating the Revolution of 1830, 'Liberty Leading the People.'
A woman of the people with a phrygian cap personifying the concept of Liberty leads the people forward over a barricade and the bodies of the fallen, holding the flag of the French Revolution – the tricolour, which again became France's national flag after these events – in one hand and brandishing a bayonetted musket with the other. The figure of Liberty is also viewed as a symbol of France and the French Republic known as Marianne.