architrave

Architrave combines the Greek archi- (ἀρχι-), meaning 'chief' or 'master,' with the Latin trabs (beam), through the Italian trave. The architrave is the lowest part of the entablature—the horizontal structure that spans the columns in classical architecture. Above the architrave sits the frieze, and above the frieze sits the cornice. The architrave bears the direct weight of everything above and transfers it to the columns below.

In the classical orders defined by Vitruvius in the 1st century BCE, the architrave's proportions varied by order. Doric architraves were plain and heavy. Ionic architraves were divided into three horizontal bands called fasciae. Corinthian architraves were similar to Ionic but more ornate. The Parthenon in Athens, built between 447 and 432 BCE under the supervision of Phidias, has Doric architraves—smooth blocks of Pentelic marble spanning the columns.

Renaissance architects revived the classical architrave from ancient models and Vitruvian texts. Leon Battista Alberti's De re aedificatoria (1452) codified the rules for each order, including architrave proportions. Andrea Palladio's Four Books of Architecture (1570) established the ratios that neoclassical builders followed for centuries. The architrave of a Palladian villa in Virginia follows the same proportional system as the Parthenon.

In modern usage, 'architrave' has also come to mean the molding around a door or window frame—a looser usage that would have puzzled Vitruvius. The structural beam became a decorative trim. But in classical architecture, the architrave remains what its name says: the master beam, the first thing the column must carry, the element that makes the colonnade into a building.