in architecture, a bay window in an upper story, supported from below by projecting corbels, or brackets of stone or wood. Usually semi-hexagonal or rectangular in plan, oriels first became prevalent early in the 15th century and were a popular way of making the most of sunlight in a northern country such as Great Britain. They were often placed over gateways or entrances to manor houses and public buildings of the late Gothic and Tudor periods. They became popular again during the revivals of these styles in the 19th and early 20th centuries.