To our medieval forebears the world could appear mysterious, even enchanted. Sightings of green men, dog heads and alien beings were commonplace. The world itself was a book written by God. But as the Middle Ages grew to a close, it became a place to be mastered, even exploited.

Mehmed II sends his elite troops into the teeth of Emperor Constantine's defenses along the city's ancient stone walls. The defenders, led by Italian soldier-of-fortune Giovanni Giustiniani, repel every attack. Mehmed's men dig underground tunnels in an attempt to shatter city walls. The tides turn against the Ottomans when a naval blockade founders.

The fantastical tale of King Arthur, the hero warrior, is one of the great themes of British literature. But was it just invented to restore British pride after the Norman invasion? Michael Wood puts the king in the spotlight.

When Mahmud Pasha and his men were crossing the river at night, Vlad Dracula started his first attack on the Ottomans. However, Mehmed II was smart enough to know that Vlad would be waiting for them. Mehmed II counterattacks Vlad’s army, and we see the first great battle here.
After his victory, Mehmed's troops advance into Wallachia, and Vlad employs guerrilla tactics to weaken his rival. At one point, Vlad Dracula released some criminals with tuberculosis and bubonic plague in order to infect the Ottomans. He sent these infected criminals to the Ottoman camp at night, and it is considered a great tactic by the experts because we see Vlad Dracula practicing biological warfare. Meanwhile, a threat lurks in the imperial palace.

The story of the British Library's Royal Manuscripts collection reaches its end with the last great flowering of illumination, in the magnificent courts of the Tudors. Dr Janina Ramirez investigates astrological texts created for Henry VII, and unwraps his will - still in its original, extravagantly-decorated velvet and gold cover. She hears music written for Henry VIII, which went unperformed for centuries; and reads love notes between the king and Anne Boleyn, written in the margins of a prayer book. Nina also visits Bruges, the source of many of the greatest manuscripts, where this medieval art form collided with the artistic innovations of the Renaissance.

Deep in the Andean mountains lays a mysterious ruin named Machu Picchu. For 400 years it sat abandoned on its misty cliff, the quintessential lost city in the jungle. Rediscovered in 1911, it contained no written records or carvings, nothing that could shed light on its history. For a century since, it has defied the endless scores of visitors and scientists who attempted to understand its purpose. Who were the mysterious people who built it and why did they build it here? Today an international team of archaeologists, engineers and scientists are finally piecing together the clues. Together they are discovering astonishing new burials, revealing the intricacies of its ingenious engineering and finally decoding the secrets of Machu Picchu.