I was in Rome last month and saw evidence of pagan temples converted into Christian churches – either by being converted for new use or rebuilt using materials from the old temple.
When the Roman emperor Constantine embraced Christianity, he set in train a process that would last centuries – of pagan temples being systematically demolished, plundered or converted to use as churches. The most dramatic example is the Pantheon – a huge rotunda with a still existing dome made of concrete, completed in CE126 under the Emperor Hadrian. Originally, the Pantheon was a temple to all the gods but after Constantine the clock was ticking against the images of deities like Mars and Venus.
Under the Byzantine emperor Phocas – who held sway over Rome and the papacy – the Pantheon was donated by the emperor in CE609 to the church. The Pantheon was consecrated as a place of worship to Mary and the Martyrs. This probably saved the building from demolition though as late as the 17th century, pope Urban VIII stripped bronze away from the portico.