A dome-shaped canopy, made of wood, stone, or metal, over a high altar. It is either suspended by chains or supported by columns. Also called a ciborium. The most famous is that of St. Peter's in Rome, designed by Bernini (1598-1680) for Pope Urban VIII. Its name comes from Baldacco, Italian for Baghdad, which furnished the precious materials for these canopies. The term is also applied to the canopies used in processions or to those placed over an episcopal throne.