Byzantium: The Lost Empire

John Romer continues his exploration of the Byzantine empire by tracing the extent of its influence abroad. He shows that the desire of its ruler to spread the word of Christianity was not just evangelical but was also a method of subduing Constantinople's potentially dangerous neighbours. By the Middle Ages, Byzantium's influence had spread throughout Europe, but in 1204 the Venetians persuaded an army of Crusaders to divert from Palestine to Constantinople. The city was decimated, the Crusaders took control and for the next fifty years systematically looted it. In 1260 the Crusaders finally left, taking what loot remained with them, leaving what was a wrecked city.

In the last programme in the series, John Romer tells how the Byzantium empire finally crumbled. Already weakened by the ravages of rogue Crusaders it succumbed to the invasion of the Ottoman empire of Turkey and the Christian centre of the world became the Islamic city of Istanbul. The scattered refugees took their art and culture worldwide, including Florence, Rome and even Romania to give the world a lasting artistic and cultural legacy that is the link between ancient Rome and Greece and the modern world.