Today it is known as Istanbul, the modern city which stands at the crossroads of Europe and Asia. For centuries past, it was Constantinople. But before that, it was Byzantium, and it gave its name to an ancient empire.

Ancient Greeks, led by a man named Byzas, founded the city in the seventh century BC. A millennium later, it was revitalised by the Roman emperor Constantine the Great, who played a crucial role in making Christianity the official religion of the Empire. When the Roman Empire in the West collapsed, it was Byzantium that kept the imperial idea alive. For centuries, surrounded by hostile neighbours, Byzantium remained a Christian city at the heart of a Christian empire. As the new religion of Islam expanded, it was Byzantium and the Byzantine Empire that stood on the frontline of the confrontation between two faiths. When, in 1453, the city fell to the Turks and its last emperor died, the world was changed forever.

The Byzantine Empire created remarkable art and architecture and a lasting cultural and religious legacy. Giles Morgan provides a concise history of a city which gave its name to an extraordinary civilisation.