pantheon (pănˈthēŏnˌ, –thēən) [key], term applied originally to a temple to all the gods. The Pantheon at Rome was built by Agrippa in 27 B.C., destroyed, and rebuilt in the 2d cent. by Hadrian. Remarkably well preserved, it is mainly of brick with a great hemispherical dome whose supporting walls are set in concrete. In 609 it was converted into a Christian church consecrated to Santa Maria dei Martiri. The term is now applied to a monument in which illustrious dead are buried. The Panthéon päNtāôNˈ in Paris was designed by J. G. Soufflot and was begun in 1764; the dome was completed (1781) after his death. An earlier church on the site was dedicated to St. Geneviève. The Panthéon was several times secularized and reconsecrated, becoming finally a mausoleum and memorial for France's illustrious citizens.