Arco di Costantino, Rome

Arco di Costantino is the immense triumphal gateway honoring Constantine the Great, close to the Colosseum. The Senate ordered it after Constantine defeated Maxentius at the Milvian Bridge in the year three hundred and twelve, then dedicated it during the celebrations of his decade on the throne. Its marble skin covers a core of brick-faced concrete, and the structure rises twenty-one metres.

Notice the carved panels and statues spread across the façade: much of this decoration was taken from monuments made for Trajan, Hadrian, and Marcus Aurelius, with imperial heads altered to represent Constantine. The result is a remarkable collision of artistic voices from different reigns, assembled into a single political statement. The long inscription across the attic credits the emperor with restoring the republic through divine prompting and force of arms.

This gateway also stood across the route used by victorious commanders processing into Rome. Centuries later, it became the finish of the Olympic marathon in Rome, won barefoot by Abebe Bikila.