Pantheon (Gr. , all, and , a god), literally, a temple dedicated to all the gods. The most famous structure of this kind is that in Rome, erected by M. Agrippa, the son-in-law of Augustus, 26 B. O., and consecrated in 608 by Boniface IV. as a Christian church, under the name of Sancta Maria ad Martyres, but which is still commonly called the Pantheon. It stands in a piazza between the Corso and the piazza Navona, near the centre of the ancient Campus Martius, and after the lapse of 19 centuries is the best preserved of the monuments of ancient Rome. It is a rotunda, 143 ft. in diameter, surmounted by a dome, of which the summit is 143 ft. above the pavement. (See Dome.) The most remarkable feature of the Pantheon is its Corinthian portico, 110 ft. in length by 44 in depth, composed of 16 granite columns, with marble capitals and bases, disposed in a triple row, each column being 46 1/2 ft. high and 5 ft. in diameter. These columns support a pediment, a large portion of the bronze roof of which was removed by the, emperor Constantius II. and the remainder by Pope Urban VIII, to make columns for altars and cannons for the castle of Sant' Angelo. Benedict XIV. removed many fine marbles from the interior to decorate other buildings.
Other features of the Pantheon, such as the bronze doors, the niches and cediculm, the marble cornice and the mosaic pavement of the interior, are in excellent preservation, and give an adequate idea of the original splendor of the edifice. An inscription on the frieze of the portico shows that it was erected by Agrip-pa in his third consulate, while another below records repairs by the emperors Septimus Seve-rus and Caracalla. It contains the tombs of Raphael, Annibale Carracci, and other celebrated painters. - The Pantheon or Ste. Genevieve's in Paris is in the shape of a Greek cross formed of four aisles uniting under a dome 66 ft. 8 1/2 in. in diameter at the base, and 258 ft. in height from the floor to the top of the lantern. (See Dome.) The height of the edifice is 190 ft. from the ground, the length externally 340 ft. It was built at the instance of Mme. de Pompadour to replace the old church of Ste. Genevieve, the patron saint of Paris. It was begun by the architect South'ot in 1764, was finished in 1790, was dedicated in 1791 as a Pantheon to perpetuate the memory of illustrious citizens, was made a church in 1822, became once more a Pantheon in 1831, and in 1853 was restored to religious purposes.
In the insurrection of June, 1848, it was a refuge for some of the insurgents, and the interior was somewhat injured by cannon balls fired at them through the west doors. In 1871 the vaults were stored with vats of petroleum and barrels of powder, the communists intending to blow up the building; but it was taken from them on May 24, and the explosion was prevented. The crypts contain cenotaphs and tombs of Voltaire, Rousseau, Soufflot, Lannes, Lagrange, and other eminent men.