from colunma Lat., a column; colonnata, Ital.; a range, or series of insulated columns supporting an entablature, or a succession of open arches : one of the most imposing works of architectural design. Colonnades are various in form, design, and application, and are composed of an indefinite number of columns. In temples and porticoes, where a colonnade of four columns support the entablature, the temple is termed tetrastyle; when six, hexastyle; when eight, octastyle; and when ten, decastyle. When the colonnade is in the front of, and projecting from, a building, it is termed a portico; when it surrounds a building, a peristyle; and when it is double, as in many of the ancient temples, it is called polystyle. The ancient Egyptians employed the colonnade as an ornament for the interior of their temples to a great extent. The Greek temples present many colonnades of great beauty and simplicity in their arrangement; but there is not any evidence that the Grecian architects ever employed coupled, grouped, or clustered columns, in any of their works.
The ruins of Palmyra and Baalbeck, the Temple of Jupiter Olympius, at Elis, and the splendid ruins of the Parthenon, at Athens, with the magnificent Temple of Neptune, at Psestum, afford, perhaps, the finest known examples of external colonnades in the world. The celebrated wings, or colonnades of San Pietro, at Rome, erected by Bernini, consisting of 280 columns, each 40 feet in height, are considered the finest architectural works of the kind in Europe. (See COLUMN, PORTICO, TEMPLE.)