Ottoman Sultan Mehmed II wages an epic campaign to take the Byzantine capital of Constantinople. Twenty-three armies have tried to take the legendary city and all have failed. Out of the carnage, one ruler will emerge victorious and shapes the course of history for centuries. For one empire to rise, another must fall.
The Ottomans, former Anatolian warlords and nomads who've built a burgeoning empire are the biggest threat to the Romans' 1100-year reign. The death of Ottoman Sultan Murad II in 1451 unleashes a chain of events that will soon bring the Ottomans and Romans to the brink of war. After claiming the Ottoman throne, Mehmed II sends an unmistakable signal to Byzantine emperor Constantine XI.

This is the story of a book that could have changed the history of the World. To the untrained eye, it is nothing more than a small and unassuming Byzantine prayer book. For faintly visible beneath the prayers on its pages are other, unique, writings - words that have been lost for nearly two thousand years. The text is the only record of work by one of the world's greatest minds - the ancient Greek, Archimedes - a mathematical genius centuries ahead of his time. Hidden for a millennium in a middle eastern library, it has been written over, broken up, painted on, cut up and re-glued. But in the nick of time scientists have saved the precious, fragile document, and for the first time it is revealing just how revolutionary Archimedes' ideas were. If it had been available to scholars during the Renaissance, we might have reached the Moon over a hundred years ago.

Andrew Graham-Dixon travels to Istanbul to immerse himself in the tumultuous world of the Byzantine Empire. He decodes the iconography of the art of the period and explains its continuing relevance.

April 1453. Sultan Mehmed II unleashes an artillery attack on Constantinople unlike any the world has ever known. It's the largest concentration of cannons that the world had seen in one place. The monumental task of keeping the Ottomans out of Constantinople falls on the shoulders of Genoese soldier of fortune Giovanni Giustiniani. He and his men must defend 14 miles of city walls. Mehmed launches his ambitious plans to break through the walls of Constantinople, but Giustiniani's mercenaries manage to forestall the attacks.

Hours before Mehmed II launches his final assault, an ominous sight shakes both sides. Rumors of a 40-ship fleet's imminent arrival have swirled for weeks, but it's exact whereabouts remained unknown. Ottoman cannons reduced the city walls to rubble, and Venetian reinforcements arrived too late. The conquest of Constantinople ushers in a new era for the Ottoman Empire, being a dominant force in world politics for 300 years. Mehmed II, in many senses, changed the nature of world history.

It's this moment where now both sides realize that no quarter will be asked, and no quarter will be given. Surrender is no longer even an option. You're in this to the end. You either die or you triumph, and there is no other alternative. Amid a spiral of brutality and low morale, Mehmed makes Giustiniani an enticing offer. The grand vizier urges Mehmed to seek a truce with his rival.