Ancient and classical

Order and proportion.

Greek and Roman

Greek architecture codified proportion in the Doric, Ionic and Corinthian orders. Rome added the arch, vault, dome and concrete, which allowed vast interior spaces.

The Pantheon dome remained the largest unreinforced concrete dome for centuries.
Classical sculpture idealised the body rather than portraying individuals.

Beyond Europe

Egyptian, Persian, Indian and Chinese traditions developed their own systems of proportion and symbolism, often earlier and at comparable scale.