The vaulting technique of the Etruscans was absorbed by the Romans, who started in the 1st cent. AD the development of a mature vaulting system. Casting concrete in one solid mass, the Romans created vaults of perfect rigidity, devoid of external thrust, and requiring no buttresses.

When was the groin vault developed?

For the first time the groin vault was used by king of Pergamon Attalos I between 241 and 197 BC. Later it was widely used in the architecture of the ancient Romans. It was also very common in church architecture in the early Middle Ages.

How is the vault created?

A groin (or cross) vault is formed by the perpendicular intersection of two barrel vaults. A rib (or ribbed) vault is supported by a series of arched diagonal ribs that divide the vault's surface into panels. A fan vault is composed of concave sections with ribs spreading out like a fan.