On 13 May 609, Pope Boniface IV converted the pagan temple known as the Pantheon in Rome into the Church Sancta Maria ad Martyrs or Santa Maria dei Martiri.
The original Pantheon had been built by Marcus Agrippa during the reign of Augustus Caesar but it had been replaced by another structure after burning to the ground. In 609, the Byzantine Emperor Phocas gave the rebuilt Pantheon to the Pope who wished that no longer would the demons be the object of veneration but rather the Mother of God and the saints.
Because the Pantheon was converted into a Church it was spared the destruction that befell many of the ancient Roman buildings during the medieval period. It has since been used as a model for many other structures including St. Peter’s Basilica and the Jefferson Memorial.
catholicunderthehood.com 