In the first episode Waldemar Januszczak looks at how Christianity emerged into the Roman Empire as an artistic force in the third and fourth centuries. But with no description of Jesus in the Bible, how were Christians to represent their God? Waldemar explores how Christian artists drew on images of ancient gods for inspiration and developed new forms of architecture to contain their art.

Although they are blamed for the fall of Rome, the barbarians were more than just fearsome warriors. Converted to Christianity in the fourth century, the Vandals, Goths, and Huns went on to produce some of the greatest artistic and architectural achievements of the Dark Ages.

To the south and east of Christendom, the new religion of Islam spread from its Arabian birthplace throughout the Middle East, across North Africa, and into Spain. As it did so, Islam imparted its own distinctive forms of architecture, ways to gaze at the stars, and art designed to depict the wonders of paradise.