A number of columns symmetrically arranged in one or more rows. It is termed monostyle when of one row, polystyle when of many. If surrounding a building or court, it is called a peristyle; when projecting beyond the line of the building a portico. Sometimes it supports a building, sometimes a roof only. For ecclesiastical architecture the most famous specimen is the colonnade of St. Peter's, erected 1665-67 by Bernini, with 284 columns and 162 statues of saints on balustrades (see BERNINI).
ANDERSON AND SPIERS. The Architecture of Greece and Rome (London, 1903); GWILT, Encyclopedia of Architecture (London, 1881).