grille, in architecture, a system of bars, usually of decorative metalwork, forming an openwork barrier or enclosure. In its usual materials of wrought iron or bronze, it has been favored for decorative treatment in all periods. Besides its almost universal function of protecting window and door openings, the grille since early medieval times has been used widely as an ornamental enclosure, especially in churches and for tombs, chapels, and shrines. An early example, of pierced bronze, is in the Church of the Nativity at Bethlehem (5th or 6th cent.). Other major grilles are those around the tombs of the Scalas, Verona (13th cent.); St. George's Chapel, Windsor (15th cent.); and the railing of the tomb of Emperor Maximilian I, Innsbruck, Austria (16th cent.). The Renaissance was remarkable for its lavish employment of decorative metalwork; in England one of the great names in the art is that of Jean Tijou (17th cent.), who executed many notable grilles at St. Paul's Cathedral and Hampton Court Palace; in 18th-century France the works of Jean Lamour, especially at Nancy, are noteworthy. But it was in Spain that the Renaissance grille reached its apex in the rejas, or monumental altar and choir screens, in the great cathedrals (see rejería). The stone grilles of the Muslim world are also famous, e.g., the marble ornamentation at the Taj Mahal.