Pantheon (“temple of all the gods”) is a building of ancient Rome, built as a temple to all the gods of Olympus. The inhabitants of Rome call it a friendly the Rotonna, or Ritonna (“Rotunda”), from which the name of the square in front of. Was rebuilt by Emperor Hadrian between 118 and the 128 d.C., after the fires of 80 and 110 d.C. had damaged the previous construction of the Augustan age.

At the beginning of the seventh century, the Pantheon was converted into a Christian basilica, call Santa Maria della Rotonda, or Santa Maria ad Martyres, which allowed him to survive almost intact to the spoliation made to the buildings of classical Rome by the popes.

Fonte: Wikipedia